So I'll take your word for it.
Well, let's say my opinion is founded on experience. But it still is my personal take on this. Oh, and I am one of the people that do not use an adblocker. If you are used to scroll past advertisements, then scrolling past unwanted games is peanuts. It helps if you are not easily offended by the existence of things you do not like.
People just experience platforms differently. For example, the Itch homepage is "hidden" to me. Out of sight, out of mind. The icon that currently looks like a pumpkin. The homepage has sections that are not easily accessible elsewhere, like the feature/fresh lists. On the bottem there even is the randomizer. It took me months to realize I could go there. After creating an account I never ever had a reason to go to the main itch.io page, so I forgot it. It is hidden in plain sight (to me), next to the browse button. This also hides the recommendations a bit. They are in your library and on the homepage. But there is no text button while browsing, reminding you that there is such a feature.
On Steam it is the reverse. The place to search by tags is rather hidden (to me).
I don't believe there would be a perfect way to address all preferences as previously established.
Perfect, of course not. But more granularity might help for certain things like maturity filterings. As far as I know Steam started pushing some kind of questions sheet people have to fill out before publishing. I imagine they would tick off a checklist if certain elements are in the game. Itch's question is not asking for facts (nudity, textual violence against children and animals, etc.) it right out asks the developer's opinion about the sensitive nature of the game and only yes or no at that. So you cannot filter out brief nudity or mild violence, but lump it alltogether with the grimdark gore games and the naughty ones.