TRAMP is unusable if you have a high-latency connection. The UI thread blocks for a few seconds after every operation, which are really frequent if you use a co

TRAMP is unusable if you have a high-latency connection. The UI thread blocks for a few seconds after every operation, which are really frequent if you use a complex configuration. The remote SSH plugin makes high-latency connections bearable, it's not perfect, but IO operations run in the background and so the UI thread does not block. I expect rewriting Emacs to use async IO to be a massive effort. It's difficult to write async code in Elisp.