Not all these foreigners are living in tourist towns. They aren't staying for a week or two, but months at a time. They aren't staying in hotels meant for tourists, but rather competing with locals for apartments (a lot of them having turned into Airbnbs because of it).
Competing over housing i quite significant if you ask me.
While OP is right in that these people are a net good for the economy at large there's a reason a LOT of countries do not allow foreigners to own property. The US is one of the few places where you can without much trouble. You can see the problem this causes with states adjacent to California, like Nevada, where the average house is now over 10x the average income thanks to the tech emigration.
Edit: No, more potential careers as an underpaid waiter or touristic guide is not an upside.
And as OP explained in the comment you're replying to, tourism is not necessarily a positive for the locals:
> That foreign money mostly goes to a handful of landlords/Airbnbs and tourist-friendly businesses (which are often foreign owned themselves). That in turn drives up prices of everything for locals – who are seeing no increase in income and moreover have to pay income tax and a ton of other taxes on it, something that digital nomads conveniently skip.
It doesn't really matter if you're a digital nomad or a classic tourist, the same downsides apply, but in the case of digital nomads they're even working while being on a tourist visa. They should pay taxes to the local administration but they don't, so that makes them a double problem.
Take a random tourist town: Say, in the southern coast of Spain. Then tell them that finally, they had managed to get rid of all the tourists, forever. Is that good or bad for the town? It's not as if there are no externalities, but in general, tourism is going to be good for your economy, and the amount of extra taxes the tourist pays on lodging is pretty low. Which Caribbean islands do better, those that have a lot of tourists, or those that don't take any external money?
Also consider what happens in the opposite side of the remote worker, where what you get is the equivalent of a foreign worker who comes in, pays taxes, but spends basically nothing, and spends all their salary in remittances, to be spent abroad by their family. The worker is competing with you for the job, but then doesn't spend it locally! You will not find many municipalities that are all that happy of having a lot of jobs formerly done by locals in offices suddenly done by someone that is far away.