While I mostly agree with OP, frankly I think this is a good thing. Touch-first games will always find their home on iPad. Touch control can enable creative gameplay not found elsewhere (even hybrids like Switch or Steam Deck; I won't play touch rhythm games on Switch for one).
I get where you're coming from, but I think the prevalence of touch first on iPad probably isn't really the App Store rules but the fact that touch is the only input you can rely on 100% of iPad users having.
Requiring every console and PC game to have touch controls inserted into them to be allowed on the iPad though means you're just going to have way less developers bothering to bring those richer console/PC experiences over. Case in point most Nintendo Switch ports don't utilise the touch screen at all.
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And I'm not even having a go at Apple about this. They can shape the destiny of the iPad any way they like and I'll probably still own one - the intent of this post is more for the person waiting for non-mobile gaming to take off on the Apple platforms. It's been long enough and the problems are pretty much permanent, so better to just go to another platform rather than wait around.
I've had a great time recently with my Switch 2. It's nice to be on a platform where you can reasonably expect more good games to be coming across all the time. Instead of the yearly keynote announcement of yet another Resident Evil, or maybe a No Man's Sky that quietly doesn't even happen over on the iPad.