Once the loudest champions of free speech because they were trying to break down the old power structures, the Left is now consolidating its power and sees no need to allow upstarts to criticize the new order.
Essentially, it's the ideology of those major corporation that want to ban all sexist and racist discourse because this sort of thing makes it harder for teams of people scattered about the world to work together. It's an ideology that's still OK with tremendous wealth disparities but which want those disparities to not be reinforced chauvinistically.
Maybe there's a part of the left outside of the USA that still stands up for free speech? Not here in the USA. That game is over. Except for a few voices in the wilderness like Brett Weinstein and Sam Harris, the left is comprised of those whose interests and actions now align with the tech giants.