Which is what /r/LateStageCapitalism, and many other subreddits, do. Only it's allowed because they are not right wing.

The anti-free speech claim is made not by judging the ban of t_D in isolation, but by looking at how their policies are selectively enforced across their platform in order to silence right-wing opinions and perspectives. In particular, support for Trump. A sub like /r/politics, dedicated primarily to anti-Trump content, is fine though, even if their users are wishing him death after getting COVID and are actively promulgating conspiracy theories.