For 18 years, ever since Mark Zuckerberg started it in a Harvard dorm room, Facebook has been growing. Through scandals, backlashes, regulatory pressure and competitive threats, it has kept growing — until now.

Meta, the new name for the company formerly called Facebook, reported Wednesday that Facebook lost daily users last quarter for the first time ever. While the company as a whole, which includes Instagram and WhatsApp, continued to grow, its flagship social network — the big blue app, as it’s known internally — stalled just shy of 2 billion log-ins a day.

The news that Facebook may have peaked in 2021 was only the most symbolic data point in a gloomy corporate earnings report that sent Meta’s stock into an epic, historic spiral — shearing $220 billion from its value and hinting that the company’s reign over online socializing might not last.

For investors, the more worrisome signs have to do with the company’s struggle to monetize Instagram’s short-form video product Reels, its answer to red-hot Chinese-owned rival TikTok; a privacy crackdown by Apple that has limited Facebook’s ability to target ads on iPhones; and mounting expenses in the company’s dramatic bid to build a virtual reality future that it calls “the metaverse.”

Use of the Facebook app itself had been leveling off gradually for years. And 2 billion daily log-ins is still an enormous, almost incomprehensible figure, greater than the population of any country.

But it’s not what Facebook was aiming for, which was to connect everyone — the entire world, even the people who don’t have Internet access yet. While it’s possible that Facebook will resume its growth in some form in the future, the quarterly decline in the social network’s most prized metric, known as daily active users, is a sign that Zuckerberg’s dream is unlikely to be fully realized, at least in the form he once envisioned.

For the average Facebook user, this may not mean much in the short run. The social network remains massive, indispensable for many, and isn’t going away anytime soon. This is not Facebook’s “Myspace moment,” at least not yet.

Rather, it’s a harbinger of a shift already well underway in Menlo Park, one in which Facebook is no longer the center of Meta’s attention or the locus of its most important innovations, but a profitable legacy product to be maintained. That diminished stature may reassure people who worry about Facebook’s impact on discourse and democracy, but it could cut both ways: It may mean that building increasingly sophisticated content policies and moderation systems becomes less of a strategic priority over time.

Meanwhile, it underscores that Instagram, WhatsApp and, increasingly, Reality Labs — the division tasked with developing virtual and augmented reality hardware and software — are the company’s future. Meta will do everything it can to keep them growing, to fend off rivals, and to find ways to squeeze more time from their users and more money from their advertisers.

When they built Facebook,Zuckerberg and company didn’t just want to build the largest social network. They set out to build something truly ubiquitous, something that everyone would use, something that would become part of the fabric of global society — something that everyone had to use, if only because everyone else was. And they got further than almost anyone could have imagined. Just not all the way.

To understand how integral growth was to Facebook’s identity, it’s worth revisiting a memo that executive Andrew “Boz” Bosworth, now Meta’s CTO, sent to the company in 2016.

“The natural state of the world is not connected,” Bosworth wrote in the memo, which was leaked and published by BuzzFeed in 2018. “It is not unified. It is fragmented by borders, languages, and increasingly by different products. The best products don’t win. The ones everyone use [sic] win.”

Facebook’s “imperative,” in Bosworth’s telling — its raison d’etre — was to be that product that everyone used, the tool that unified at last a fragmented human race in a single, vast network. And the company would pursue that imperative at any cost, even the cost of users’ lives, “because that’s what we do,” he wrote. “We connect people.”

Bosworth later insisted, once the memo had come to light, that he had written it in the spirit of debate, and that he didn’t really believe what he wrote. Zuckerberg said the same. Yet the company’s actions have borne it out again and again over the years.

It wasn’t even enough for Facebook to connect everyone in the world with an Internet connection. In 2013, before its user growth began to slow globally, Zuckerberg — who is always thinking long term, always anticipating the threat that’s over the next hill — foresaw that Facebook would eventually be constrained by the reality that roughly half the world lacked reliable Internet access. So he devised a plan to connect “the next 5 billion” by offering a limited, Facebook-centric version of the Internet free to the world’s poor.

Called internet.org, and later rebranded as Free Basics, Facebook’s moonshot largely missed its mark, making gains in some key markets but falling short in others because of public mistrust, digital nationalism and the company’s overconfident approach. Still, Facebook continued to grow as more of the world came online without its help and it started a major push to get more international users in 2014. Even in 2018, when the app’s usage in the United States and Canada plateaued for the first time, it was buoyed by growth elsewhere.

But Tuesday’s earnings report showed that Facebook’s ascent has stalled just about everywhere. The biggest decline in daily usage was not in the United States but in a category that it calls “rest of world,” including Latin America and Africa. The company added that data plan pricing increases in India last year also contributed to slower-than-expected growth.

All of which casts Facebook’s dramatic renaming and pivot to “building the metaverse” in a new light. Zuckerberg knew before just about anyone else that social media was no longer enough to keep the company on top. Now he’s trying to will into existence a grand new vision of a digital world in which we all have second lives that play out through avatars inhabiting virtual spaces and realms.

Zuckerberg has a long track record of reinventing Facebook and has been compensating for the big blue app’s deceleration for some time. Several years ago, the company realized that it had saturated among U.S. and Canadian users, and it overhauled its core news feed algorithm to prioritize engagement — getting existing users to spend more time on the network.

It also bought Instagram and WhatsApp, Facebook properties that are continuing to grow even as the product Zuckerberg built as a college student is peaking. And losing users does not necessarily mean losing money in the short term: Facebook’s revenue per user also continued to grow last quarter.

To regain its footing, Meta will have to strengthen its focus on growing and making more money off Instagram. It will have to deliver on plans to make its various services more interoperable on the front and back ends — for example, by giving people who use Messenger the ability to connect with sellers on Instagram.

Its success in potential growth regions such as Africa, where Facebook is hugely popular, also still depends on broadening Internet access. Less than half of the people in sub-Saharan Africa have smartphones, and many have limited bandwidth on prepaid phones, according to the GSMA, the industry organization for mobile network operators worldwide.

Meta reported Tuesday that Reality Labs is growing rapidly, though its expenses are mounting faster. Perhaps someday it will be Facebook’s metaverse that connects us all, at last.

Yet the end of Facebook’s growth era marks a turning point in the history of social media and the Internet. If Zuckerberg couldn’t connect the whole world with Facebook, given all the resources and momentum and desire one could ask for, he may have to confront the possibility that no singlenetwork ever will.