I believe they're protecting the mainstream (their captive market, their cash cow, their future) away from the one thing that could ruin things: the truth.
So yeah, we should shun and/or fight these evil tech giants, for sure. I use them against themselves, I give them little, but manage to help many. But that time too is coming to an end, with the recent rounds of bannings and censorships. The YT changes coming in December are truly disturbing.
When we leave these sites and withdraw our support, it's a good thing in many ways, but it also means we're essentially giving up on the mainstream, who are pretty much going to their destruction at this point. Maybe that's how it has to be, and maybe we did all we could when it was safe to do so, and now we have to duck n cover.