> What about mounting a remote file system over sftp?

That can be OK for some tasks, but not others. For example, TRAMP will execute commands on the remote; so commands like M-x find-grep-dired will be faster when using TRAMP.

> Install EMACS or whatever editor you prefer on the remote?

There's actually a lot of flexibility there, since Emacs is perfectly usable in a text terminal, which could be run over SSH; it can also show X11 windows over the network (though I recommend the "lucid" build, rather than GTK); and it also has a client/server mode.

installing an editor on the remote sure works - my mention of vim was not an accident, it is my preferred remote editor. some of us are bitextual ;-) - but then you lose the seamless remote+local editing, need to sync your config, potentially clash with someone else’s (ever ssh into ubuntu@awshost?), take special care not to sync any private stuff, etc.

as for sftp, unfortunately that’s not an option if you happen to use windows locally eg for work reasons, nor if you use a mac as of several years now, since fuse became closed source.

not to mention, again, the fact that you are limited to whatever root you decided to mount, limited to editing as a user that i’ve already mentioned, as well as limited from using remote tools as sibling stated. try making a git commit over sftp.

if you have a focused “working on a project” workflow it may work, otherwise PITA