Being reliant on a single OS permanently nailed to the hardware is no less crazier. I'd like to be able to install another OS on a vulnerable device, it would help tremendously and not only with the security of that specific device.
Now I've got some expensive paperweights that I can't even use as such because every time I see them I have the urge to throw them in the trash can.
Provide a way to unlock the phones and a standard BSP, it should be the law.
LineageOS has a build roster of current devices at this URL:
https://lineageos.org/Changelog-30/
The Pixels are the most flexible, but don't buy a model from Verizon (they don't allow unlocked bootloaders).
Most other OEMs require you to generate an unlock token and send it to them, then wait a week, which is extrememly inconvenient (and sometimes they just stop and refuse, as I understand OnePlus has).
If you want a locked bootloader at the end of the process for security, then you will be on a later Pixel with Graphene.
Sorry for the cynical take, but patronizing folks like this is worse than cynicism because it suggests that you actually believe what you're saying is true.
Locking OS upgrades to a network vendor is substantially crazier. It creates pockets where the hardware vendor ships a security update but your network doesn't care to ship it and isn't incented to. It is BANANAS.
I understand that most U.S. banking apps work on Graphene.
As far as contactless payments, try a Pixel watch. I understand that it is entirely separate from the phone.
However, Google Pay will certainly run on my Lineage OnePlus 5. It will not provision localhost, but I am guessing that it will provision a watch.
I would go buy the parts and try it just to know, but I doubt interest would remain here by the time I assembled everything.
Edit: Graphene has a page on this subject, and Garmin appears to be the best option.
https://discuss.grapheneos.org/d/1040-compatibility-with-sma...
If you don't know what to do with it because your security standards are so high, just give it to someone with lower standards then you, or use it for some project that doesn't involve sensitive data. And if security is broken to the core, there is probably some vulnerability you can exploit to root your phone and do whatever you want with it, including installing a custom ROM.
Still, I agree with you on making it mandatory to provide an unlock method, at least for out-of-support phones.
Just silently enlisted into a "Residential VPN" and a background script that checks for the SSID "Iranian Research Facility" every time you turn your wifi on for some reason.
Sure, a thief may pick your lock, but unless he knows there is something valuable in there, he will probably go find a car the owner forgot to lock, it less effort and there are plenty of them, or he may look for more valuable targets.