Also a limiting factor on turboprops (due to their larger diameter) run at a much lower rpm… they’re geared down quite a bit m.

This is a complicated area, but in general basically: Supersonic flow is bad. At best you get a ton of noise (like the Russian Tu-95). Efficiency also goes to hell.

This is also why the SR-71 had those crazy moving brake cones… they manipulated the shockwave so the air actually entering the engine was subsonic.