To me, the question would then be - what are we getting out of it?
With iOS, the value proposition is clear. Apple has aggregated the best customers in the world, which translates to more money for developers even after paying Apple their cut. Consumers get a curated App Store which is generally safer, and this had led to consumers being more trusting and being more open to purchasing apps. Apple has also introduced features to streamline the overall process, from iTunes (developers never get our payment information), subscription tracking, ATT and Sign in with Apple.
So while many people may argue that Apple doesn't deserve 30% for its efforts, my argument is that Apple at least deserves something for the role they have played in growing the overall pie for everyone.
In contrast, if Microsoft is just going to allow any app onto their platform willy nilly, and not even do the bare minimum to screen out the bad actors like malware and viruses, then what exactly are they collecting a commission for? I would expect them to at least do something to streamline the overall process of downloading apps, such as managing updates centrally or letting me authenticate purchases via biometrics.
Therin lies the difference.