companies/customers don't want files to be on laptops in non secured places
A generally valid concern, though full-disk encryption resolves this pretty nicely. My laptop is better secured than most data centers, from a realistic threat vector standpoint.
companies/customers may block any access except a remote desktop, ensuring not data cannot be transfered out of their network
This is just bonkers security theatre. I understand you might not have control over it, but given how easy it is to transfer data over remote desktop protocols (hint: most of them actually enable copy/paste between local and remote buffers!), there's simply no validity to this type of restriction.
tools are on the server and need the files. I don't want to commit things just to find out it does not compile.
That's where editing via remote mounts come into play (e.g. SFTP). The file remains on the remote server.
the download/upload process is just too tedious
More tedious than a remote desktop connection?
Having an editor that work on that use case is a must for most of people working on Linux servers.
Most? I'd venture to say that most Linux servers probably don't even have a UI environment. At least, the vast majority of the servers I've worked with in my career. I've done plenty of remote editing over SFTP on Linux servers, but almost zero remote desktop with a GUI editor running on the remote side.