It's good that they are doing this, but Linux support across the board is abysmal. I don't think Linux users should have to expect the bare-minimum out of a company that charges high prices for their service.
Even though I am on macOS, I have thought about leaving them, too. Mostly because I am paying a lot and their tertiary services such as calendar, drive and pass are lackluster. It feels like I am paying a steep price for them to focus on offering new products that are worse than the competition. With things like 1Password and iCloud drive (with advanced data protection enabled), it is hard to justify paying Proton hundreds of dollars for Mail and VPN alone.
Linux isn't supported for their drive stuff likely for the same reason Backblaze's BB-Personal programmer said they won't even though it's easy. Linux users tend to be more of power users and data businesses thrive on people using less than they pay for (800gb or less for BB).
I would like to see more Linux love as well. I think both companies could be more transparent and even if Linux were treated differently, having options would be cool.
Same. Terrible linux support for their vpn (on top of all the obvious issues it has, it also requires networkmanager which I don't use, and iirc doesn't support ipv6) drove me away, tuta has been much better imo. Especially since tuta on android doesn't depend on google play services (proton mail does), which should be basic functionality for a privacy focused service