Replacing transatlantic flights is out of the question (for batteries for now). But there exists shorter routes, and according to this list [1] on Wikipedia, the busiest route in the world is 449km long. That's probably also not doable now, but maybe in some years?

For the first years it will probably only be a few wierd, short routes in rich countries like Norway with 110% financial support from the state. But when they can safely fly 5-600km there is a actually quite a number of routes with a lot of passengers out there.

1: https://en.m.wikipedia.org/wiki/List_of_busiest_passenger_ai...