It's a global far right power grab fueled by money from Russia using weaponized disinformation. It's been going on for decades at a smaller scale before Facebook, etc, even existed. It's also fueled by conservative dark money groups funded by conservative billionaires. You should read the book Dark Money, I highly recommend it.
Even the antivax stuff is from Russia and it way predates the big platforms. It was started in the crunchy mom communities on Livejournal, where they first experimented with seeing if westerners would glom on to weird mommy trends like not using shampoo, nursing your kids to ridiculous ages, "unassisted birth", which is where people deliver babies without any medical care at all, "unschooling", etc. That took off in a big way and then they began with the antivax stuff, and used Livejournal as a tool of Russian government propaganda.
Then they started funding white supremacist groups, and the groups like the yellow vests, Moms for Liberty, etc. Really recommend learning about dark money and Russian weaponized disinformation.