I've fallen into that trap plenty of times, so I get it completely. You end up with a bunch of pretty books on your shelf that you read three chapters of and then abandoned. The people who mention the algorithm rewarding visual stuff have a point, but here's the thing: some BookTok books actually work beyond just the cover.
The difference is in looking for recommendations in older reader communities, not just TikTok. Goodreads is useful, but also book forums where people have been discussing what really stuck with them for years. A lot of times the books that blew up on BookTok two or three years ago are still being read and talked about in those spaces because the book actually has substance. If you see something mentioned both on TikTok and in those older communities, then it's probably worth your time.
My recommendation is that before you spend money, check out free samples if the digital format is available, or borrow from a library. I mean, if the first chapter doesn't grab you after reading opinions from people who aren't chasing virality, then you've saved yourself some cash. There are good books that came through BookTok, but you need to filter them differently than just counting how many times someone recommends it in 15 seconds.