So, while I 100% agree with the original premise--that Instagram is filled with ads and content farms, with relatively few "real users" to be found--this specific complaint is actually "a you thing": Instagram's feed algorithm ranks content in ways that seems to give the wrong players power (such as by giving more weight to people who merely steal and aggregate content than the ones who produce it), but it isn't entirely incompetent.
I am, thereby, going to claim that, if you are getting nothing but half naked women on Instagram on your feed, it is because you actually "wanted" to see half naked women (...maybe "merely" subconsciously! as, while I am not entirely sure about Instagram, TikTok is apparently tracking implicit watch time more so than explicit actions, and maybe you stop for just a bit longer on such content as it catches your eye).
In contrast to your experience, I recently went through a devastating breakup, and my algorithmic Instagram feed seriously has no half naked women on it: it is, instead, nothing but an intense pile of captioned voices (like, an audio with text, but not video of that person) saying pseudo-motivational quotes about relationships ("if she had wanted to make time, she would have" sort of shit) with inspirational background music overlapped with videos of people "making stuff" (such as carpentry).
It is demoralizing to experience: I go into Instagram for whatever reason, start scrolling by accident, and then a half hour later I am at the bottom of a pit of emotions crying my eyes out while clutching a pillow and I am lucky if I escape even an hour after that :(... but, the algorithm does't care about my mental health: it only knows that if it shows me videos that cluster along these axes I apparently am willing to spend the rest of my life watching ads (which make up about 1/4th of the content on Instagram).
