One big reason Nim never really caught on is because we've got lots of fast-ish languages with garbage collection (like Go, which sucks a lot of oxygen away from Nim IMO). Rust introduced a new concept to the mainstream that lets you program safely without a runtime hit for garbage collection.
You might like Total Annihilation and its modern descendants, like BAR or Zero K. There's still some micro depending on the variant, but the focus is much more heavily on macro, along with making the units smarter.
Apart from that, the Civ games are turn-based, but scratch a similar itch as RTS games
Snapcast on a RasPi will handle that great