I'll admit that I haven't had battery problems for a long time, but I still think that this is a great idea if it can prolong the usage of other hardware.

Usually the software bugs down before the battery, and even with replacement batteries there will still be an issue of what to do with the spent batteries. Can they be revived or clustered for other purposes etc.?

I know that used batteries from cars are still valuable as storage even when they are at half capacity or less, but phone batteries are so small that it isn't feasible.

Hopefully this will push the manufactures into a different direction than the current use and discard strategy. European companies will soon have to file environmental reports, but with batteries coming from Asia, I'm not sure what effect EU will have. Chain responsibility isn't really there yet.