Isn't this already happening between companies? If people really prefer WFH jobs, then WFH employers would be able to lower their wages. Doing it within companies will be tricky though, because apparently you lose around a third of the benefits of in-office work if even one person is remote[1].
[1] "I think another possibility, and there our paper gives a little bit of evidence, is that if you have even one colleague who is remote, that yields about 30 percent of the loss from having everyone be remote." https://www.theatlantic.com/podcasts/archive/2024/06/remote-...
50% is absurd, but in general full-remote companies that know what they're doing are already sort of doing this—forgoing location-based pay and offer a consistent rate anywhere in the country.
That rate will be lower than what they were paying for people living in the tech hubs (maybe in some cases actually 50%), but represent a major pay bump for people in the rest of the country. It's a win-win for everyone except the people who really want to stay in tech hubs.
Location-based pay is not the same thing because location-based pay pays more to people who live in SF but don't ever go into the office than it does to people who live somewhere else and don't go into the office.
Location agnostic pay comes close to what OP is suggesting: put your pay in the median of the country as a whole and pay that consistently to everyone regardless of where they live. The company saves money by not having to match tech hub prices, and there are tens of thousands of developers across the country who would love to accept a pay scale that's weighted higher than their local market by the tech hubs.
https://www.minimalcompany.com