Proton isnt great for oldies. You cant use default email apps and the like without a bridge, and last I checked they arent available for mobile or Chromebooks, which means they would have to use the first party app. Thats just another change thats not worth it for oldies who dont like change.

Also migrating away from protonmail is a nightmare. You cant when set a “forward all” rule.

I admire protons ethos, but the UX sucks.