Drew Austin is a writer and urban planner in New York City. He's also something of a Twitter addict.

Since Elon Musk acquired the platform in October, Austin has noticed his Twitter feed devolve into an engine of self-promotion for the billionaire's constantly shifting whims.

"To be honest," Austin said, "the biggest change I noticed right away when he took over was just that everyone was talking about Elon all the time. And all the content that users were generating was Elon-orientated content, which I found really annoying."

No matter, Austin is sticking around, like so many other Twitter users.

Some outside researchers have observed a small dip in usage since Musk assumed the reins, but in general people are still logging on.

"I've basically been using Twitter for 15 years at this point, and there's no way to quickly replace the followers and following that you accumulate over that amount of time," Austin said. "Twitter is still the default. It's the Schelling point — where everyone is."

As most daily users are quick to point out, Twitter has become clunkier, glitchier and less relevant than it used to be. Nonetheless, nearly six months into Musk's control, no serious competitor has emerged, leaving some wondering what more it will take for everyone to leave for another social media site.

"More than any other platform, it gives us a sense that we're witnessing the world beyond us, but in a really visceral and personal way," said Shannon McGregor, a social media researcher at the University of North Carolina at Chapel Hill.

"It makes you feel like you're in on the joke of the day," she said. "And people don't want to miss out on it."

Twitter, like TikTok, has a big advantage: 'network effects'

Another place where everyone on the internet seems to be: TikTok.

But its future is uncertain. The Biden administration has threatened to ban TikTok if it does not divorce from its China-based corporate parent company, ByteDance.

That has left many wondering, why hasn't a U.S. tech company swept in and built its own version of the viral video app.

Some analysts note TikTok's "secret sauce algorithm," as the reason for its formidable dominance.

But the reason TikTok is so hard to replace is the same reason people can't seem to quit Twitter: The so-called "network effects" of both platforms.

It essentially means that the more people join a platform, the better it becomes for everyone. Each user's individual experience and contribution adds value to the whole network.

"The idea is that you have to reach critical mass and before you do that, it's not a super valuable service. But after you reach that, it's very hard to beat, because it's very hard for others to replicate," said Zsolt Katona, a business professor at the University of California, Berkeley, who studies social media.

Decades ago, economists used it to describe the usefulness of fax machines, then the workings of the internet. And more recently, academics have studied social media's ills through an understanding of how network effects operate.

"And the reason this is called 'network effects' is because usually this value is realized through some sort of networking with an actual link between two people," Katona said.

Twitter competitors falling short amid platform's problems

In the case of Twitter, that's a link between 237 million monthly active users. On TikTok, more than a billion people worldwide.

On top of that, many on both platforms have found niche communities around food, music, politics, memes, and whatever internet topic du jour is driving the conversation. Leaving for a smaller alternative can often feel like part of the community's vibrancy is missing.

Nonetheless, there have been a crop of challengers that have tried to seize on the disarray at Twitter, but, so far, there is no clear winner.

Mastodon, a Germany-based Twitter alternative, has gained traction in recent months, but because of its somewhat complicated "decentralized" structure, navigating the platform has proven cumbersome to many new users.

Another Twitter rival, Post, allows users to make "micropayments," to publishers so that individual news articles can be read without running into a paywall, though it has not gained much momentum yet.

"I think the reason people have stayed on Twitter is that despite all of the issues with it, it still seems to be working better than these other platforms for what people want it to do for them," McGregor said.

With Musk's crack down on national media organizations like the New York Times and NPR, some journalists are pining for a text-based, real time social media platform not controlled by a singular billionaire, but no such site has raced to the front of the pack.

"One of the reasons people are staying on, myself included, is that this isn't the first time bad things have happened to people on Twitter," McGregor said, noting how Twitter can be a place where harassment, trolling and direct messages being flooded with vitriol is not uncommon.

When the platform becomes 'uncool'

Even on huge platforms that have the benefit of network effects, copying a service does not mean it's going to take off.

Instagram introduced a TikTok-like feature called Reels in 2020, and it just has not come anywhere near threatening TikTok for a variety of reasons, including that the recommendation systems and basic features are very different.

Another factor is that when a big social media app tries to mimic a competitor, it usually does so as a kind of side experiment, not the main service of the app, said Julian McAuley, who studies social media at the University of California, San Diego. Reels is being heavily promoted by the app, but not at the expense of Instagram's endless stream of hyper-glamorized photos.

"An obvious reason why Facebook or YouTube or whoever else doesn't implement that way is because these big incumbents are very reluctant to cannibalize what's already working well for them," McAuley said.

Another way to think about the network effects of social media is that the popular ones are sort of too big to fail — at least it seems so right now.

But they can falter. Other social networks like MySpace and Vine had their moments, only to eventually fade into obscurity.

There are three possible reasons network effects can backfire, according to research from Catherine Tucker, a professor at the MIT Sloan School of Management.

For one, a site can become too noisy or congested, leading users to seek out more curated communities.

Some people might become concerned about how their data is being used on a large platform and might try to find a more privacy-preserving alternative, as well.

And finally, once a platform becomes too mainstream, it could be seen and "uncool" or too predictable, prompting users to flee for more insular platforms.

Social platforms rise and fall with internet fads. And experts say when a new app becomes all the craze and amasses a huge network, Twitter and TikTok might find themselves in the social media graveyard with Myspace and Friendster.

Though, as technology writer Casey Newton wrote recently in his newsletter Platformer, journalists covering the tech industry do not appear to be ready to bolt from Twitter, despite all the upheaval.

"For the moment, though, Musk has learned the same lesson Jack Dorsey did: Twitter is extremely hard to kill," Newton wrote, referring to the former chief executive of Twitter. "And for the journalists who have come to rely on it, there is almost no indignity they won't suffer to get their fix."