I work at tiktok in mountain view and this article seems exaggerated. I don't know about the UK office but while there are may be folks in the US working 996, most of my peers do not have that schedule. If I were to stereotype with my biases, I'd say the hours would be similar to a FB/Amazon (>=45 hrs/wk) than a Google (<=40hrs) but that some members of teams here may also have 1-2 nights a week with 7PM calls (10AM Shanghai). Although, if you're a team lead or manager, you may have more frequent alignment meetings.
I think certain teams and functions may have higher demands perhaps due to lack of resourcing, sudden business priorities, or a need to resolve ambiguities during the transition of a scope but it feels like it's getting better overall. From my experience, people will work overtime if needed but definitely not for the sake of a 996.
We've previously spent a lot of resources also looking for ways to render native components through backend APIs (there was a team called screenflow that was laid off) but this was complex and wasn't able to support complex business needs. Uber does not want to remove app size at the cost of UX (ex. webviews).
I feel that new personalities would just take their places given TikTok's would just push different videos should some leave. Since the magic of TikTok is the "for you" page, if reels does not replicate well then it may not take away a significant share. While instagram stories hampered growth from snap, they've also seemed to have some failures ex. competing against twitch. There were some tournaments hosted on the fb gaming platform but it seems like many of them have returned to twitch.
Perhaps you are engaging with these videos you are not interested in by finishing the videos, etc.