I think there is currently Tumblr, Twitter, Mastodon, Bluesky and Facebook.
Anything else?
In other words, the status quo in the West is basically as follows: you can say whatever you want, so long as it doesn’t actually have any effect.
that’s not how advocacy works. you have to at least have a target demographic / group. not to mention a campaign plan etc etc. then you can start looking for the tools that fit your advocacy.
According to statistics from Priori Data, no idea how reputable this site is though
https://prioridata.com/data/social-media-usage/:
But they have different demographics and depending on the matter you want to advocate for the topic may be more suppressed on some, for example Facebook and especially Twitter moderation can be bad on leftist or antifascist content.
I would think the best is to use as many as possible if you want the highest reach, it’s possible to have accounts that repost from other sites if you don’t want to manage multiple. Facebook has high numbers but tons of bots, same with Twitter.