KDE presents For Activists, a page that guides you through free open source tools to effectively organize rallies, privately communicate with fellow community members, and safely manage your own grassroots movement
Man these showcases are great. They give you a quick overwiew of the available software and are managing to keep it focussed on particular use cases. Probably the best introduction to Linux software I've seen so far.
I knew neochat existed but wasn't able to use it as it didn't used to support end-to-end encryption, but I noticed recently that they've added support for it so I've switched. It's been great, I use matrix both at work and at home and I love being able to native implementation.
Definitely worth giving a try if you haven't already.