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.
I think for your use case Signal could be a good alternative, don’t listen to what people say, I would rather encourage you doing ylur own research on Signal and other recommendations you might gonna consider.