Munro took apart a Nissan Ariya which has this exact kind of motor. The maintenance is basically removing a tiny cover and replacing the tiny and cheap carbon brushes every 100k km or more. It's basically cabin filter level maintenance.

And they said that PMSM motors are more efficient at low RPM, but their coils get saturated at higher RPMs meaning they lose efficiency at highway speeds (which actually affect the range number people car about).

So overall not such a bad tradeoff, if it makes cars less expensive.