There's a big difference between a completely optional "recommendations" area and a loop. If the recommended stuff happens automatically without you having to look for it, then it's a loop.

So Spotify is a loop (it automatically plays the next recommended song)

Yep - some emotional core of my being (not rational) hates ML recommendations.

I'm a happy paid user of Spotify and just ignore the recommendations (I'm not looking at a screen), and I use YouTube heavily with a browser plugin that hides recommendations (which kills the end of video loop). I get recommendations from people, and use the products for curation, bookmarking and subscriptions. They're good.

Whereas Instagram and TikTok are vacuous and useless to me - I can't make myself use them. I think my brain knows what's wrong with them, and makes a kind of disgust reaction very quickly.

I agree, there's a very low level, emotional difference between them. I'm not sure I could encode it in law, but it is different.