In my experience it's absolutely true. Maybe it's just early in Instagram's phase of their new feed and it's not optimized, but all I see are a bunch of seemingly random memes and videos that don't interest me at all, and they only appear targeted to me in the most superficial of ways. Essentially I skip past the videos looking for friend photos, and after about 30 seconds get bored and shut the app.

TikTok on the other hand seems to know me better than I do myself (or care to admit). I go out of my way to not open it because I know 30 minutes of my time will vanish in an instant.

https://restofworld.org/2021/instagram-and-class-in-india/ I saw this last year and it does a great job telling the story of how Instagram's recommendation engine biased towards "elites"

Very true, but partly due to the broad content variety TikTok has. Their tools to help creators are excellent and they do a lot to promote highly niche content.

Instagram is a clunky mishmash of features rolled out in desperation. TikTok may suffer the same fate eventually, but I think they are years away from that.

It's algorithm is way more aggressive than other social media. Sometimes it's almost creepy. I don't care about a lot of stuff on there but it's easy to find yourself in very niche communities on tiktok.