Yeah, that's the problem with these things: they're wasting assets. If you want maximum longevity on your phone, not only do you need replaceable batteries but to purchase the absolute maximum storage so you can benefit from wear leveling on the flash. And even then, it will still slowly degrade over time.
Google tried to build a modular phone and ended up cancelling the project in part because these systems are essentially an SOC surrounded by support hardware. Still, I'd buy a modular phone or at least one that allowed swappable batteries because Android phones are still a beast on battery thanks to all the background services and large, power hungry screens.
Porkbun