^{This article originally appeared on Business Insider.}

By one important measure, TikTok didn’t grow in the final quarter of 2023. In the U.S., it actually went into reverse.

This is shocking for an app that has experienced rocket-ship expansion since the Chinese tech giant ByteDance launched it in 2016.

The question is why? A few folks might be deleting the app. More likely: There are simply no more hours left in the day for people to watch more TikTok videos. This is especially true for young users who are now entering a new busy time of life known as adulthood.

Here’s the data. This chart is probably way more worrying for the company than any possible U.S. ban.

TikTok’s growth rate slows

These numbers are the growth rates of daily average users, or DAUs, for some of the popular social media services globally. This is from a quarterly review conducted by Evercore ISI analysts who tap Sensor Tower data.

After demolishing the competition from 2020 through the first half of 2022, TikTok’s DAU growth rate has collapsed. In the fourth quarter of 2023, the video service lagged Snapchat, YouTube, Instagram, and Facebook. Yes, you read that right: The ancient big blue app grew faster than TikTok.

TikTok did not respond to a request for comment.

What is going on?

One interesting theory is that TikTok users are growing up and taking on new responsibilities that leave less time to watch videos.

When the app launched, it took the world by storm. Young kids and teenagers were especially drawn to the service’s unique creator-friendly content and culture.

Let’s say those users were about 13 when they first downloaded the app in 2016 and 2017. Now, these people are at least 20 years old. They have full-time jobs or are studying at college. For many, their parents no longer do their laundry, cook their meals, and ferry them to and from sports games, meetings, and other engagements.

For readers who have not yet experienced this, it’s called “life.” This stuff takes a lot of extra time, which leaves less for TikTok.

This shows up in the data, too. TikTok’s US average monthly users between the ages of 18 and 24 declined by nearly 9% from 2022 to 2023, The Wall Street Journal reported recently, citing analytics firm Data.ai.

“Time spent” has been the part of TikTok’s business that really caught investors’ attention. US adults were expected to spend about an hour a day in 2024 on TikTok, more than YouTube, according to eMarketer estimates.

More time = more chance to show people ads and do other things that make money. If some of TikTok’s core users can no longer afford to spend an hour a day on the app, that’s not good for business.

Remember Brielle?

This gives me a new appreciation for the honesty of a TikToker called Brielle, who was unfairly lambasted last year for complaining about her new corporate job.

After landing her first office role out of college, she posted a video describing how little time she had left each day for a personal life and basic chores. Older viewers harshly criticized Brielle for being naive and a host of other alleged failings.

What I now realize is that Brielle was probably just a heavy TikTok user who had recently grown up and realized she no longer had as much time for the app.

Deleting TikTok

I’ve seen this in my own life. My two kids have been huge fans of TikTok for years.

The older one is now in her second year of college, studying mechanical engineering. She rents a house with friends. There’s a huge study load, along with house cleaning, cooking, doing the dishes, emptying the trash, paying bills, and yes, parties.

A couple of months ago, she decided to delete TikTok from her phone. She’s part of a competition in her house right now to see who can limit screen time the most.

A year ago, this daughter watched at least two hours of TikTok per day. I’d given up trying to limit this. She’s an adult, and I have no sway anymore. And yet, she recently realized by herself that she couldn’t fit in all her new obligations and still watch TikTok for hours every day.

My younger daughter lives at home and is still in high school, so her daily TikTok intake is still massive. She’s leaving for college in the fall, so she’ll eventually face a similar dilemma with her time.

This is not just me

The Wall Street Journal recently interviewed a few TikTok users in their 20s. They tell a similar story: They started noticing that TikTok, in particular, got in the way of sleep, work, household chores, and relationships.

They also said many of their friends have deleted the app or scaled back their use in recent months.

Keilah Bruce, a 27-year-old accountant, told the Journal she stopped using TikTok last year.

“I’m at a good place now with my friends, my family, my dishes, and my laundry,” she said. “I don’t want to sacrifice those things anymore.”

“TikTok offers several tools, from custom screen-time limits to sleep reminders, that are used by millions of people to help them make intentional decisions about how they spend their time,” a TikTok spokeswoman told the Journal, adding that the app regularly reminds people of these features.