i'm talking about two things specifically: MFi, whatever they did to deviate from BLE for airpods advanced modes.

There was also something specific for Apps to make them behave as you want with accessories, you had to go through something simillar to MFi or work around with hacks.. but i really don't remember what that was called. we made do with workarounds years ago and never thought about it anymore

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.