You are thinking the classic hub and spokes transport network where you have to travel to a major city with an actual bullet train station travel to another big

You are thinking the classic hub and spokes transport network where you have to travel to a major city with an actual bullet train station travel to another big city at high speed and then do an uber/taxi/whatever to get to and from the station on both sides. In the extreme case, this would be more of a point to point kind of thing. Walk to the nearest flat surface where one of these things can land and wait a few minutes to be picked up. Your local super market's parking lot would be big enough. On the other side, you land at a similar venue and then walk to your destination in a few minutes. Most cities could end up with hundreds or thousands of suitable locations for these things to take off and land long term. So, about similar to the density of subway stations or better. But a lot cheaper to build.