Quite right, on the constructor part... that is very much the appeal for us techies. But they do spend 100 million tweaking the last 0.1% of aero advantage and tire-deg management. a) They could just homologate a common engine, like in F2 and concentrate on the chassis or b) make a properly designed hybrid PU. By (b) I mean have an E component that gets adequately charged... the MGU-H (E-Turbo) of the last generation seemed to work fine. The current specs is nuts, definitely NOT advancing technology.

Banning teams like Ferrari or Mercedes from competing with their own cars (including the engines) would be the end of F1. The current regulations are extremely ambitious such that constructors can get a significant advantage from developing better tech. And it's working, the Mercedes powertrain is clearly dominating, even though the Ford V8 is more powerful.