Bridge for Linux is not "completed"
Another link here is listed as "completed" [https://protonmail.uservoice.com/forums/284483-feedback/suggestions/32772520-protonmail-bridge-for-linux]
A closed-beta that you have to email and request an invitation to is not a "completed" project. It's been two years, and the paying Linux users deserve the same kind of service as the other platforms.
Moreover, there are many routine problems with the Bridge program. connection time-outs, etc. Please go through Bridge and polish the rough edges.