

This is now fixed, but you didn’t used to be able to filter excluding game tags on Steam.
Though Steam doesn’t have a single unified search interface. You’re probably referring to the most-comprehensive one, the one used on the Steam Store after you’ve performed a search. That one does have “exclude tag” functionality now. But there are a bunch more, which have varying levels of completeness in functionality. For example, the list that comes up on the store when you click on a sale. Or the list of games in the sidebar in your library. Or the list of games on the “shelf” in your library, in the large pane. They don’t all support the same criteria.
I have before commented to say that I wish that they’d unify all their search interfaces.
yt-dlp
supports a number of video streaming websites, not just YouTube.