Re: Solve the aging problem
I had an iPhone 6, whose battery eventually got to be not serious. £25 for Apple (well, authorised Apple people) to replace it, which took an hour, sometime in 2018 I think. That's probably a little more than the battery would have cost, but the whole 'you can't replace batteries in phones' thing is a huge red-herring: you can. perhaps if you buy a phone from a company which doesn't take support seriously then it's a problem, but the solution to that is to force companies to take support seriously.
I finally replaced the phone last year because I decided running non-current iOS was going to result in possible risk: that's a problem I'd like not to have, the battery thing was fine.
(Note this reads like an Apple fanboy comment: I'm not, but they were OK in this regard.)