I just saw today that there is now a desktop app in beta for Windows and macos. As a privacy conscious person on Linux I am stuck as a second class citizen using proton services because there are no Linux apps besides bridge.
not to be a jerk but there are much smaller companies than them that have linux developers. Or they take some in house people and say hey learn how to develop for linux. It's actually not that hard ( source: I am an Engineer for a software company for 12 years )