I can tell you that I have heard from the manufacturers that the encased rechargeables have dramatically reduced moisture repairs. I have no idea to what extent that has been offset by battery repairs. The cynical person would expect that the battery should die at exactly the day that the manufactures deem the hearing aids too old to repair.
I am not actually that cynical, however–I think that generally the manufacturers ARE trying to make the best possible product to beat out their competitors and increase their profits and that includes actively trying to increase reliability. They can always come up with other reasons for people to upgrade. 
You’re ignoring this member’s posts.

