I think you focus too much on the consequences of unpopular speech that do not constitute a stifling of free exchange of ideas, namely public criticism and not being published in the private publication of one's choice. Neither of those things curtail anyone's speech and it would be false and naive to state that they do. The only actions that have a real chillng effect on debate are the firing from one's job, say at a university, which by definition is supposed to be a place where ideas can be exchanged freely in the shared search for truth and regardless of outside censure. If a professor is fired it should be for misconduct, incompetence, or failure to produce enough output (the latter 'publish or perish' rule at many universities may be debateably unfair, but it is not censorship.) Again, if one group at a university wants to hear a speaker and invites that speaker, another group who does not want to hear him/her should not be allowed to block that person from speaking. Again, this may not be against the 1st Amendment, but it is alarming and does have a chilling effect on debate.
The fact that such firings and deplatformings have been brought about by a small mob of people, sometimes without trial or debate, is what is most alarming. Of course you may conclude, as I have, that those institutions that do not defend their professors' rights to express their views have invalidated themselves as places of higher learning and must not be included in our definition of the "academic world." The fact that so many once great institutions that championed free speech and open debate have gone this way is deeply disturbing.
And again, to try to discount these encroachments on the free exchange of ideas in this country by comparing them with actual police violence is a logical fallacy. We could dismiss anything by comparing it with something many degrees worse. For example, we could say, "How can we complain about any free speech violations in the U.S. when there are countries where you can be put to death for blasphemy? " Who cares if you're being evicted from your apartment when people are being shot in war zones? Who cares if you lost your leg when some people were born without any limbs?