TRAMP does not work like that. First it does not have a whole directory tree, rather it just caches the opened buffers so things like grep etc. must run remotely which sucks on a high latency link or could be much slower if the server is not very powerful VM. Second at least like 5 years ago when the last time I played with TAMP it worked really badly on an unreliable connections or when the laptop switches to different wifi network. If ssh connection hangs, the whole GUI often hangs and sometimes after reconnecting I had to throw away resent edits and reopen the buffer. It could be that nowadays things are better, but for me nothing beats my lsyncd + explicit remote command script. Even file completion works with trivial efforts. As paths in my local tree copy matches the remote paths, completing by files just works, and it is trivial to call completion scripts for remote command from the completion script for rc.