There isn't a dearth of social media. There are a couple of GIANT social media websites that have sprung up in the last 2 decades, but there are dozens of semi-popular niche-ier forums that cater to any rant you might want to leave.
That's the point. FB/Twitter are now public utility size and usefulness. Your blog, not so much.
But also just because they are big platforms why does that give people a right to be on them? Is my speech less free because I have a smaller audience?
It is democratized moderation. If your following is small enough to skirt the mods, then you can post what ever you want. If your following is huge and you post a bunch of lies about sewer mutants, or that the covid vaccine gives you rabies, or that Hillary Clinton is actually a space alien in cahoots with Planned Parenthood to subsist off the flesh of aborted 6 year olds, then YES, they will remove your posts, and potentially ban you for a period of time.
This literally happens to my aunt every few weeks. She gets a weeks long ban for basically reposting only Russian spam, gets her account back and does it again. It has never even been permanent.
The amount of eyeballs available today for even small sites is far greater than it used to be pre-facebook.
That worked when there were more than two platforms to post your opinions on.