Late to the party but Microsoft's arguments fall flat for me, at least with regards to Apple and Google, moreso Apple but can give Google _some_ credit on this one.

Neither "forces" their respective browser in the same way that Microsoft does. Putting iOS aside for a minute to be addressed later, on an Apple device, the number of times you will get a pop-up telling you how insecure and slow and bad other browsers are is practically 0. Apple has the MacOS spam banner, but either they've toned it down or walked it back completely based on my experience purchasing an M1 this year. Never did Apple try to make you use Safari as your PDF reader, it doesn't change or add shortcuts for Safari on updates, it doesn't insert a banner on other apps or locations to tell you to use Safari, changing your default browser is as simple as opening System Preference and searching "default browser", then picking another one, and MacOS doesn't say a word about it. Spotlight is the one place that might surprise people but even it respects changing the default browser and will search on your set one.

Google, as annoying as it is, also doesn't seem to care much which browser you use on Android; I don't own a ChromeOS device so no idea what it's like on that, but you're free to install just about anything and set it as default without so much as a hiccup, and similar to Apple, I have not seen it try to set itself via other common OS features. Granted, Google is a dick with Chrome in many other ways (other commenters have already noted how they use their control of the web to force Chrome), but I don't quite put it in the same way.

iOS is special I guess in that you can install any browser "skin" you want, but it's webkit underneath. I'm mixed on this as I understand the arguments against this and it's definitely not good on Apple, but at the same time, if you're talking about what browser to use to get the features like sync, iOS lets you do it without a peep from iOS about it and for the grand majority of users, the rendering engine isn't what they care about, it's the other features of the browser which you can happily use. Still not good you can't use another engine, but I would still put it in the "okay, but needs improvement" area.

All of this compared to how Microsoft handles Edge on Windows is a pittance. They really want you using Edge for everything, and there are so many system hooks that open Edge without you wanting it to. Changing the default is much more daunting, and it's far too easy to let it get set back (in general I've noticed Windows has some weird stuff about default applications in Win11. It might just be the release we use for our lab environments, but it refuses to let me set notepad++ as default text editor without resorting to the command line, but it could be just a strange situation).

I have a hard time seeing this as anything but Microsoft muddying the waters with such arguments and I definitely don't see them as good faith. I suppose it's just good business sense that they don't try to tie Azure features/performance to "best viewed in Edge" as I imagine an exodus towards AWS/GCP, but for the mythical average user, they do a lot to get you onto Edge no matter what you actually want.