Add to that the fact that mainstream social media companies wouldn’t touch DDoS and CSAM attacks with a 100-foot pole, even if they contracted with a third party. Both of these attacks are highly illegal and would surely ruin a publicly traded company (or one that’s trying to go public, like Reddit).
And don’t forget Russia in your list of state actors who are threatened by the unrestricted flow of information. They definitely don’t want their citizenry to be informed of how disastrously their invasion of Ukraine is going, or what a murderous scumbag Putin is.