Ok, so Facebook knows I have a VR headset and bought some games, and they're using that information in targeted advertising (as much as things like EU law allows them where I live)? Quite frankly, I don't care - this doesn't really affect me in any practical sense - and again, thanks to existing laws, I can actually opt out from a large part of it.

From a practical standpoint, I would have a much bigger problem with a situation that exists with Google, where some people had access to their email and other services disabled, because some stupid bot classified their comments in YouTube livestream as spam with basically no recourse until the story blew up in tech news (https://gamerant.com/markiplier-stream-ban-lock-users-out-of-gmail/). The root of the issue there is that those accounts just shouldn't be linked, and what you do on YouTube shouldn't affect your access to your own email etc.

You may argue that this is simply down to the fact that Facebook doesn't have a strong enough market position to get away with such practices, and that they would do it too if they could, but as it stand today, the giants like Google or Apple are far worse. (And with most of these problems, as well as other monopolistic practices of tech giants, regulation can be a large part of the solution.)