San Francisco was inexpensive up through the 1980s, and the non-commerical creative side of the city started draining out in the 1990s (first slowly, then much more quickly -- it's all long gone now. Apologies to anyone who would like to believe otherwise :).
This is also true of New York, on approximately the same timeline.
In the early 2000s, Austin and Portland tried to take up the creative mantle, with some success. Both are struggling to maintain it now, for the same reasons but on a slower timeline.
Cheap rents are a prerequisite, but there are other sparks required for a place to catch fire.
I don't know of any US cities that are doing anything interesting today. Not at the scale of SF and NYC certainly, but also not even at the scale of 20ya Portland and Austin.
I think part of the issue is that rent is not adequately cheap in any US cities now that have critical mass plus tolerable living conditions (climate, economy, politics). This worries me.
Edit: More specifically in terms of cost of living anyways.
Then we got Uber and Google, and our nationally-cheap housing prices have jumped up closer to the norm - which is too high for the bottom half of earnings population.
Indianapolis has been going through the same thing (we are getting some of the overflow from the housing crunch in Nashville, etc.)
I snagged a house at a decent price last year after looking for over a decade.
Agreed that being two hours from Atlanta is too far for high relevance.
Outsiders hate being excluded though so the barriers all get knocked down. In face our modern social norm considers any kind of exclusion a moral failure, even excluding people who dislike the social norms. Maybe this results in a more efficient (perhaps even more pleasant) society but the cost is unique local culture.
If it might make money, it'll get amplified.
We were drowning in crappy corporate driven pop prior to that for years (with bright spots like techno, industrial, etc.)
(But I reckon cheap rent, leisure time and a laissez faire attitude to drugs are almost always in the mix).
Because after a certain point I realized- lots of places are cheap (sure slightly less now) but not everywhere is going to produce some kind of large scale cultural movement.
The one that a lot of people seem to know is Detroit- for the last 20 years everyone has been saying wow, lots of artists, wow, you can buy a house for $10 or whatever, but that hasn't been enough.
Sadly a part of me believes that maybe physically localized culture isn't a thing anymore with the internet. Being able to make beats / tiktoks anywhere is too much of a counter-force to people being in the same physical space, no matter how much people seem to love the idea- and this is the true boring reason why this doesn't happen anymore, not that *blame the boomers* rent has gone up.