A bullet train is better if there's one that already happens to go from your location to your destination. If they manage to make these VTOL planes safe and cheap enough, they'll be far easier to deploy than any train system. Also while there's overlap between short haul aviation and train markets, the infrastructures don't have to be mutually exclusive.

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.

I would say, at least in the near/medium future, the fact you'll never hit a traffic jam for a 1 hour commute is a big plus.

But then again, weather probably will ground it more often.

The ultra rich in London, NYC, and LA: you can live 2 hours as the crow flies by car (which would be 3-6 hours depending on traffic) and cut it to an hour or less.

Or you can plop your floating megamansion offshore and commute to the city from there.

Bullet trains are point to point, and you have transit to station overhead. This is more direct above and beyond an absolute speed advantage.

A small town doesn’t have the density for a HSR link, see eg China’s HSR debt.

A 120 mile link at 14 million a mile is more than a billion dollars.

New train lines won't be built ever again in the United States