Changable batteries, maybe, for the environment. But I’ve never used a phone long enough for this to matter because unoptimized software starts crippling phones after 4 years anyway.
This is absolute bollocks. Unless you are buying dogshit budget phones, they all continue to run fine after 4 years. I have phones from 2017 and 2018 that continue to operate without major issue today. Until very recently most Android phones weren’t even receiving feature updates beyond 4 years so I suspect you’ve just completely fabricated this story to justify your upgrades.