You probably haven’t seen paid ads for those things recently. You’ve almost certainly seen them in the years past whether you realized it or not unless you were just not on social media around the time it was actually affordable (like around 2013 putting in even $10 could get a decent response resulting in people actually showing up where as by 2018 you could piss away hundreds just to hear crickets, probably worse now but I’m out of the game).

The distinction you are trying to make is one that only existed in the distant past of chronological timelines where ads were an interjection into the natural flow of posts, ever since algorithmic timelines took over there is no such distinction anymore it’s all just shit trying to compete for attention.

Ads are shit but ads existing is not in of itself enshittification. Enshittification isn’t just about things sucking because of capitalism (it’s not even an anti-capitalist concept) but a specific process by which a captive market is created exploiting each class in turn. You need to read about enshittification from the source on pluralistic.net instead of trying to reverse engineer it from webcomics.