It's a no brainier, until you deal with standardizing the battery and attachment mechanisms across many manufacturers. Then figuring out the machines necessary to automate the process of removing the battery and swapping in a new one. Then dealing with people who abuse their battery and bringing them to EOL early. Then deploying all of that nationwide.

Oh, and it limits where you can place the battery. You can't integrate it into the frame, which has some big advantages in reducing weight.

Conversely, charging stations are relatively easy. You need to standardize the plug, which ain't nothing, but it's far easier than an entire battery release mechanism. The charge stations themselves aren't much more than a transformer, some high voltage electronics, and some controls. Again, not nothing, but way easier than an automated garage for battery replacement.

Charge stations were always going to be able to race way ahead in deployment timelines, and we still don't have enough of them. If we had focused on battery swap stations, we'd be even further behind.