[pjmlp]

> In GUI-land, this is hardly ever the case. I can't compose different software together, which is something I do all the time with the shell.

Assuming those programs have been written to be usable from the CLI to start with.

Likewise GUI applications can be written to be automated by REPL environments automation, specially if the OS exposes application IPC like COM, DBUS, XPC, Binder, REXX, ....