What I would like to see, not sure if covered here already or already available on the market, is electric power tools from various manufacturers (AEG, Bosch, Makita, Ryobi, DeWalt ...) to work with same batteries.
(I have no idea if such a standard exists.)
The only potential downside I see is perhaps an increase in unsafe counterfeit batteries. Annoying as it is, I
do understand why so many device manufacturers use authentication chips to prevent third party batteries, given that (Samsung’s Note 7 fiasco aside), most cellphone and digital camera battery fires are apparently due to third party batteries, if I remember correctly.
So strictly from a product liability perspective, there is logic in attempting to keep out batteries you didn’t make yourself.
The only products I’m aware of where standardized third-party batteries are the norm is broadcast video equipment, where the industry-standard “V mount” is used for tons of cameras, etc. (In the past, it was common for the camera to have one, the video tape recorder another, maybe another for the audio recorder… All interchangeable.) A company called Anton Bauer is dominant, but many, many competitors exist.