I don't think you're entitled to an equivalent phone. If we're talking patents on essential things like a cryptographic algorithm required for banking or a technology required to implement 5G, sure, the patent holder should be required to license the patent to anyone at a reasonable price. But not licensing patents on non-essential features like Face ID or health monitors are OK. And all of that is independent of whether or not you can install your own software.
What matters is the competitive situation. Given that you're practically required to have either a Google or Apple device to participate normally in modern society, Apple and Google should be precluded from forcing customers and suppliers[0] to use their other services, like payment services, app stores, delivery networks, ad networks, etc.
But if Apple were the 4th biggest phone platform with at most 10% of the market, Apple would definitely be entitled to remain a walled garden. Even if their phones had features no-one else can implement due to patents.[1]
0: E.g. app developers
1: I'd claim this is the only position that is consistent with being in favor of patents. But I'm mildly anti-patent, so YMMV.
I don't think I'm entitled to an equivalent phone either. I merely think I'm entitled to either (at Apple's option) an equivalent phone OR apple not using it's monopoly on producing equivalent phones to extract further money from me after patent rights are exhausted at the time of the purchase of the phone from Apple.
I.e. I'm entitled to anti-trust protection. Or I'm entitled to patent-misuse protection. I don't really care which set of laws you put it under.
Even if Apple were 10% of the phone market they would still have 100% of the distributing software to devices with Apple's patented technology market, and that should be enough for anti trust protection to kick in.
(I'm also mildly anti patent, but I've been carefully selecting only arguments in this thread that I believe are entirely consistent with a pro patent belief system. E.g. if Apple treated their phones like their laptops - where they also have patents - all the positions and arguments I've taken would not have an issue with their behavior)