Personally I've played devil's advocate for Google and Apple mostly because the reasoning I see for forcing them to open their platforms seems post-hoc. For instance many assert that phones need to be open but, for some reason, game consoles do not. People seemingly deciding what they want and then twisting their reasoning until it fits.
Also, never have I seen a pop-up in iOS to tell me to use Apple Maps when I opened or downloaded Google Maps. Again, very strange, because you are claiming that Apple is doing the same disgusting tactics as Microsoft, yet I have never felt as an iOS or macOS user to be bullied into using Apple Maps.
On my laptop it's super easy. I opened Safari, went to the Firefox website, then downloaded it. At no point whatsoever did Apple bully me into not downloading Firefox.
So iPad is not a computer? What is it?
General computing devices enable you to install software freely and use it however you'd deem fit. Desktop computers are general computers. So are laptops. And for the vast majority of people, an iPhone or Android device are general computing devices. However, the Android device allows the user to actually do 'general' things like write code and develop software on itself. While the 'i' device doesn't.
The issue is that the 'i' device is often sold as a 'general computing' device like all other smartphones and computers.
The issue with the 'Tesla' computer is that it isn't a general computer. The purpose of the device is solely to control and manage the vehicle.