Yeah that much is clear. I still find it fascinating though that in one case I accept a platform where basically everything I interact with is an ad (like Steam), while otherwise I reject ads that are tacked on from the side (like YouTube).

In case of YouTube it should be guiding me towards interesting content creator videos about things I might buy (like video games I'm interested in). YouTube just needs to find a way to get a chunk of my purchase money from Valve if I end up buying a game on Steam after watching a Let's Play video for that game on YouTube.

But that's something for YouTube to figure out, not me ;)