>>skille+(OP)
I feel like the elephant in the room is that there's no phone battery that's going to stay useful in anywhere close to that time frame, and replacing phone batteries is usually a losing proposition. I've tried, several times. Fake, low-quality batteries are rampant (usually degrading within weeks), and genuine ones are prohibitively expensive -- usually a significant fraction of the cost of a new phone.
>>wheels+B7
I'm using a phone right now that I bought in 2016. The battery lasts me the day more or less.
I bought a pixel just recently because Slack told me my phone is too old for them to support, and I need it for work. The camera is messed up on this phone, but otherwise, I would happily keep it another few years.