government regulation to force companies to begin using a modular system
Yeah, that's fair. But the issue is also similar to cell phones.
Each battery is unique because it needs to fit the unique layout of the vehicle. Not to mention the battery tech is moving so fast, that the chemistry of the battery itself is changing every few years.
I suspect China's approach to a vehicle where you hot-swap the batteries instead of charging will be the way it goes. Someone will do it, it will be most $$$ efficient and therefore profitable, and then it will force them all to adopt the same approach.
hahaha... it saddens me that only those >30yrs old may get this.