Probably 'stuck underwater' is the key phrase here.

I'm attracted to the idea of battery submarines mostly because you'd be latching onto a huge (and growing) commercial development world. Much less need for highly specialized tech.

Thinking it through, assuming that propulsion is the gating factor for submarine adoption (maybe it isn't), what happens when pretty much any nation can afford a silent undersea navy?

The next thing I'll hear about is recharging station surface ships.