I kinda struggle to believe it's that difficult. I mean, Tresorit has a pretty good and functional Linux client. What have they done which makes it sustainable for them?
Filen.io also has a pure sync-client, which is distributed as an AppImage. This also works, but the FUSE integration Tresorit provides is quite awesome and performing quite decently.
I would actually recommend Proton to start the development on an older Linux distro. Like RHEL/Alma/Rocky 9 or Debian 11 (which is EOL, though) and make it run there. Moving from that distro to newer distros will then go smother and you'll get other distros supported quicker.
The mistake too many Linux efforts does is to take the "latest and greatest" distro version - often coupled with what a single Linux developer considers the "most used distro" and then hits lots of challenging when needing to support older distros. That's going to be painful.
@protonprivacy Please take note and forward to Andy and other managers.
@jon@vivaldi.net I use a plethora of browsers.
I'm migrating fron Firefox to LibreWolf (sorry, I prefer non-chrome based browsers), but have a Ungoogled Chromium as a backup those times Firefox/LibreWolf doesn't cut it (I thought the world had learnt a lesson from the IE days; seems we need to educate a new generation web hipsters).
On Android I use the default browser (in @e_mydata@mastodon.social) for a few news/blog sites, Mull and Vivaldi for some other sites and DuckDuckGo when searching. Default browser is Mull with Privacy Mode enabled by default.
I honestly don't like that the Chrome based browsers seems to be dominating these days. We need a heterogeneous web render environment to ensure a single dominant player dictates how things will be for users.
And without such competition, I fear there will be a lesser drive to further improve browsers. Just like when Netscape seemed too complacent with their own browsers back in the days.