Well, the digital nomad doesn't spend a lot of money. Some on accommodation, some for internet, some for food, and that's it. He spends his time remote working on his laptop. His income is paid offshore.

Apart from the tourist aspect of it, the point of a digital nomad is to save money on rent, food and taxes, not to spend all your money in a foreign country.

Of course, a business hub, or a technological hub can attract digital nomads punctually, even if accommodations are more expensive.

Now Japan has a problem with its age pyramid and desertification of its country side. So it should be possible to attract digital nomad for longer and cheaper stays, even if they don't have a lot of money (to spend in Japan), at least that's good for the young body count, and perhaps they'd eventually fixate and have families. But again, this wouldn't be a six-month thing, they would have to add more incentive (free or $1-house in the countryside with minimal occupancy, good internet connection (I don't know if Japan has 100% territory fiber coverage) (that said nowadays there's Starlink), etc.