There are many reasons why there are two separate apps and not necessarily related to how addictive the algorithm is. The "source" you linked gives one such reason:
> Like other social media services in China, Douyin follows the censorship rules of the Chinese Communist Party. It conscientiously removes video pertaining to topics deemed sensitive or inflammatory by the party, although it has proved a little harder than text-based social media to control.
Also have you used Douyin? It's really feels like basically the same thing.
https://apnews.com/article/gaming-business-children-00db669d...