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.
I didn’t reply to the insulin pump part, sorry. It was toward the other part, which implied to me that there are people who don’t want to deal with cables, so no one should be about to use them.