My cynical take is that a lot of the people for whom the tiktok algorithm "didn't work" simply weren't pleased by what the algorithm (correctly) thought of them. It's like the 40 year old truck driver that complains it's just hot girls dancing. No, my dude, you just ALWAYS stay to watch the girls dance, you just don't want to admit it.

In general, it "just works" after a short period of maybe searching for specific terms just to "seed" the algorithm.