I went to see if Douyin is different, and found this on its wikipedia page:

TikTok and Douyin have almost the same user interface but no access to each other’s content. Their servers are each based in the market where the respective app is available. The two products are similar, but features are not identical. Douyin includes an in-video search feature that can search by people’s face for more videos of them and other features such as buying, booking hotels and making geo-tagged reviews. Since its launch in 2016, TikTok/Douyin rapidly gained popularity in East Asia, South Asia, Southeast Asia, the United States, Turkey, Russia, and other parts of the world. As of October 2020, TikTok surpassed over 2 billion mobile downloads worldwide.

Some users may find it hard to stop using TikTok. In April 2018, an addiction-reduction feature was added to Douyin. This encouraged users to take a break every 90 minutes. Later in 2018, the feature was rolled out to the TikTok app. TikTok uses some top influencers such as Gabe Erwin, Alan Chikin Chow, James Henry, and Cosette Rinab to encourage viewers to stop using the app and take a break.

Many were also concerned with users’ attention spans with these videos. Users watch short 15-second clips repeatedly and studies say that this could report to a decrease in attention span. This is a concern as many of TikTok’s audience are younger children, whose brains are still developing.

so the only diferences are different servers and environment, and some extra features on Douyin (one of which relies on facial recognition, which means they scan videos for faces and identify them). honestly it seems to be even worse than instagram or youtube :|