Let me preface this by saying I have no idea what Paris in the 20's was really like outside of what are almost certainly stale tropes in my mind (but possibly accurate ones).

I will say this about Detroit though. It is currently undergoing a developmental revival that may or may not last, and this development is built on not just a cultural revival, but a creative, determined, DIY culture that was never not there in my lifetime, and did not need to be reintroduced.

Sections of downtown are experiencing a renaissance. Other parts are crime ridden, cheap, terrible, unique, beautiful, and all sorts of other things. The creative class is definitely flowing into Detroit right now and has been for years. I travel to the East Coast and out West a couple times a year on buying trips for fashion & apparel. I've met more than one indie designer in the past few years that, when they hear we live in the Detroit area, say something along the lines of "No way...a got a bunch of friends back in Cali that were talking about just moving to Detroit and getting an old warehouse...just to you know, make art and clothing and stuff."

In my lifetime I've witnessed Detroit about to "come back" about 3 times now. Something is different this time, though who knows how it will play out. That uncertainty is what the vanguard creative class is built on. There is a lot happening in Detroit creatively right now.

Finally, I should note that a terribly large number of the population of Detroit is overwhelmingly impoverished, unemployed, under educated, and black. When you look at conversations like these, most of the residents would probably just shake their heads and wonder wtf. They don't need a cultural scene. They need schools that don't systematically fail their kids, neighborhoods that aren't havens for violence, a chance in hell of getting a job, and something in the way of city services in exchange for their taxes (for those that can afford to pay them). The creative revival in Detroit is stimulating, vibrant, frenetic, life-giving, lauded...and completely overrated with respect to the amount of progress it represents in local popular culture imho.