I'm sure if you install some version of Linux in your iPhone you can do whatever you want. But you're probably using iOS.
This is pretty much the whole reason the GPLv3 exists.
No obligation to help vs actively hindering are not really the same thing.
Anything requiring a single android component goes in the “doesn’t actually work” category.
Neither is nice but at least iOS gets updates.
I don't think you're going to really be able to reliably avoid the problem that very very very few people outside of AOSP are doing any work on OSS for phones.
They sell products. Those products have well-known rules. If you don't like the rules, don't buy the product.
An argument can be made that it's morally wrong, but if you're going down that road, there's a lot of things should be morally more compelling than Apple's AppStore policies.