With completely wireless earbuds, the rule is: when the battery fails, they have to be disposed of. Not so with the Fairbuds, that allow you to replace batteries in just a few seconds. Combined with a repairable design, the earbuds should therefore have an extremely long lifetime.
The bootloader is open so you could throw Fairphone’s Android on there no problem. I think they provide the files for that (didn’t check so don’t know for sure)