Devices want to be portable. the competition for weight and size is very high. It's ironic how as usage of phones increased considerably with social apps, people seem to not have a problem with thicker iPhones for larger battery. The current iPhone 17 Pro is a chonk that would probably have been considered bulky and backwards 10 years ago.

The trends decide the standard. Many EVs use 18650 but I can see that for competition and weight reduction they may switch to a more proprietary standard like blade batteries in BYD for competition. It all depends on where the competition is going with it.

For earwear, I would say that portability and weight is a big area for competition.