What the OP presumably means is that they just have a local copy of all the files. Then you only edit local (with LSP, gdb, etc.) and any change you make to a local file is mirrored back to the remote copy automagically.
This won't work for things that use a docker container without wrapper scripts, but those have their own problems.
Which means you can’t remote LSP, gdb, etc.
In other words, it only works if your local platform is the same (or compatible) with the remote platform, or (in a limited capacity) if you have a viable cross compiling environment.