More remote work isn't going to make a significant number of people want to stay in these uneducated, economically-depressed locales. They aren't just leaving for the work, they're leaving to get away from the local culture.
There are generally some more educated pockets within these regions that are actually quite desirable, but lack economic development. These spots, like Asheville NC (the place I ultimately would like to settle down in) are unfortunately quite expensive due to low housing supply and people from out-of-state moving in. But I've got a remote gig now, so I just need to save up more. Personally, I will be happy to be part of a culture that values friendliness, ingenuity, sweet tea and banjo music.
Fwiw, I tried moving away to Seattle, but despite my educational attainment and liberal leanings, I found that I just prefer NC. There's something to be said for living somewhere you don't feel like an outsider. After 5 years in Seattle, I still couldn't lose that feeling.
Similarly, we worry about disrupting natural biomes through deforestation or overfishing, but we don't think about sustainability applied to human communities, with a few exceptions (reservations get some attention, though not sufficient attention).
What do we do? For one, I don't think it's hard to make an ethical case for remote first workplaces.