If you can't communicate with anyone you can't make the world a better place.
Tell that to Jadav Payeng, who planted a forest by himself. He accomplished, on his own, more for the good of the world than most communities on Facebook ever will.
https://interestingengineering.com/science/jadav-payeng-the-...
Maybe that's why OP is looking for an alternative to use for communication and organization?
We could communicate more effectively 20 or so years ago. Communication technology had already matured, but we didn’t have these engagement-driven social media platforms. The goal of these platforms isn’t to communicate, it is to sell ads and pick engaging posts to re-broadcast.
What gets people engaged is stupid anger. Even stuff I agree with on some fundamental political level, the social media version is just stressed out, to the point of being ineffective and often wrong in detail.
Centralized as driven social media can’t go out of business fast enough.