AFAICT MFi was for Apple proprietary connections - lightning, AirPlay, CarPlay, etc. I haven’t looked, but isn’t the situation with USB-C and driverkit much better?

I don’t see an issue with companies doing something proprietary as long as their standardized connections - Bluetooth, WiFi, USB - work as expected. Nintendo not supporting standard USB-C devices was always crazy. Try connecting wireless headphones to an Xbox or PlayStation that aren’t certified; unsupported because they don’t think it provides low enough latency.