Basically any OS can install any compliant terminal emulator, meaning the cases in which you really have to patch your TUI for another OS are few and infinitely more manageable than GUIs
Compliant with what? The proposal is "throw out all the compatibility and build some other kind of terminal" in which case nothing is portable.
Compliant with what? The proposal is "throw out all the compatibility and build some other kind of terminal" in which case nothing is portable.