But that's not what is actually happening on these platforms.
You can search for something like "is coronavirus dangerous to me" on YouTube and you'll get a list of specific banal videos, which don't actually answer your question from about 12 months ago. It almost looks hardcoded. You can tweak the search parameters and you'll get the same thing - videos which talk about coronavirus, but not the thing you searched for.
No other topic has this applied to it. If you search for e.g. "is the ryzen 7 worth it" the videos vary, they're not all adverts from AMD and they will answer your question.
We're not talking here about what's on the front page or marketed, we're talking about explicitly searching for material and having that be hidden from view i.e. censored.
If I go to the library and pick up a copy of the communist manifesto, or Mein Kampf, or a book on Stalin, or whatever, the library isn't _promoting_ those at all, they're not expressing an opinion. There's been a weird shift in discourse recently (see no-platforming) which implies that allowing something to exist is promoting it.