Okay, that's a lot to read and respond to ;-)

Let me first address your remark:

this is not about free speech, per se, but it is about the culture of silencing.

In the current situation, these are intertwined. Governments have "asked" MSM to focus on what they considered "correct information" and everything else is not shown, or shown as being extremely bad or even just plainly incorrect.

Part of the silencing, although (self-)censoring is more appropriate, is caused out of fear. Another part of it seems to be a deliberate effort the create changes we don't want or need.

This makes any form or normal discussion impossible.
Especially when you have a right-wing view you must be stopped at any costs.

At least, that is the situation in Holland, and what I can tell in the rest of Europe as well. East-Europe excluded maybe.

Youtube

Of course, a company may decide what they do and don't allow.
I think it's clear that the company that had in its code of conduct and as their slogan "Don't be evil", has done a 180-degree turn-around and are part of the system and problem.

The way Youtube now determines what they deem to be information that must be allowed is completely unclear, and opposing their decisions hardly ever has any effect.

Unfortunately, I find Steemit not to be censorship-free either.
Due to the way Steemit is created, content is hard to find unless you're looking for it or stumble across it, and the downvote possibility is, in my opinion, a clear censoring tool.