I don't use SimpleX, but it's hard to argue against a well developed open source privacy focused messaging app. There are a million "privacy-focused" messengers out there with various flaws around security or sustainability. Matrix is great but the goals seem a little different. Plus, it wasn't that long ago that Matrix was struggling to find funding.
Why would you want this over matrix, anyway?
It feels like matrix is THE choice at this point, once elementx comes out i'm gonna bother to try to get people to switch.
save