Yes, Proton Drive for Linux is currently not being actively worked on/update: they lack developers, see post
Update: i went to reddit because there was an AMA from proton . There, they said:
*The only reason why our Linux clients are lagging from a development is simply that it is extremely difficult to hire Linux Desktop developers.
Still reading all the replies, very greatful for the tips and responses, thank you all!
===
Thought i would share this with you all:
I contacted Proton for a technical issue and decided to also ask about their plans for Drive for Linux.
Their response:
Proton Drive on Linux: Regarding the availability of a Proton Drive client for Linux, this is a common feature request that many users have expressed interest in. Our team is aware of the growing demand for a Linux client. While we currently do not have an ETA for when a Linux client might be available, we have not ruled out the possibility of working on it in the future.
I'm very disappointed, since i'm probably going to switch to Linux over the weekend.
Come on guys give them a break. You dont have to use their services if you dont want, but they do a variety of things and they do them well. You can still use Drive through a browser.
Proton is super easy to use. They are a gateway drug into privacy. Its close enough to google for any pleb to use. If you are using linux, then you probably dont need to be airplane spoon feed privacy.
They're obviously talking about the sheer number of users. Windows has something like 10x as many, which most people know. From Wikipedia:
For desktop and laptop computers, Microsoft's Windows is the most used at 69%, followed by Apple's macOS at 21%, and Google's ChromeOS at 3.7% (in the US up to 7.9% ), and desktop Linux at 3.2%, so on traditional PCs Linux sums up to 7% share (ChromeOS is a different OS, but regular Linux can be added to it).
So Linux only wins if 100% of their users use it and only 10% of Windows use it, which won't happen. Of a company has limited resources, they're obviously going to focus their efforts on where they can attract the most number of users (and most money). In this/most cases, that's Windows.
A higher return on devs' effort (meaning more users reached and more profit) and thus the effort and focus of said devs, which is the chief complaint of the OP and relpies. Apologies, thought it was obvious in the context.