We need a better cross-platform terminal! Not editor. The current state of cross-platform terminals is fairly poor. Other than Alacritty[0] there hasn't really been any new innovation here.
Terminals have been slowly improving. Bracketed paste is now universal (I pushed this into xterm). Micro is using shift-arrow for selection. JOE uses Ctrl-Arrow, because when it was implemented, Shift-Arrow did nothing on most terminal emulators.
So here's an example (pet peeve): in Micro (and JOE with mouse mode enabled), you can select text while holding the mouse key down. If you move the mouse out of the frame, it should autoscroll to keep selecting more text. Unfortunately terminal emulators send no codes when you move out of the frame. (I submitted a patch to fix this for xterm, but still not in...)
and as for moving the state of terminals forward:
https://github.com/kovidgoyal/kitty/blob/master/protocol-ext...