Thats my point you don't need a new phone every two years, at three years I notice a slight decrease in battery life, I would imagine it will keep being useful for another two easily and I could take somewhere to get a new battery if I really wanted.

On the other hand I have old windows phone devices that had replaceable batteries I never utilized as they stopped updating the software after a year. Sounds like the Android side is similar. My Apple device have been some of the longest lived useful computing devices I have used even with the difficult to replace battery.