I tried SimpleX but the VPN kill switch on my phone prevents syncing with my computer.
I use telegram primarily as a note taking app with sync features.
Occasionally I send files to friends, so having easy set up for tech illiterate would be great.
Friends used telegram so I had the app installed. It was easier to store documents in telegram than in one drive or proton drive, so telegram became my go too. Obviously not the best setup, but it worked and was easy. I’ll try out Signal and Matrix, but continence is a big factor in my choice.
Proton drive has free tier. Not sure if it is as easy as tele for doc storage but holy-shit tele really doing it.
People rave about it.