Agree, zoning laws here are not meant to hinder new construction just control it's use. However, permitting went from ~30 days to about 6-12 months in Dallas. Supply is still causing a shock and construction just takes longer now as materials get delayed, etc. and it messes everything up. The trades are less capacity. They stayed busy though lockdown, or moved back to their native country to ride it out. I know several that just never came back. There are a lot of contractors turning builders, some delay due to their inexperience, but I don't see that as a widespread issue. But all in all, you see a lot of construction around but it's actually probably less finished goods than what was occurring in 2019. The lack of property and prices means people are building on any dirt they can find. I've seen some insanely horrible tracts of land get developed because all of a sudden, prices being what they are, it now finally makes sense to invest $250K in dirt work. I've seen land that has been for sale for 10+ years due to nobody wanting a 100% flood zone get developed in the last year; again because there's nothing better available and people have the $ to fix invest in drainage.
Dallas itself is competing with it's suburbs, Plano/Frisco etc. The development you see was planned 2+ decades ago and really only a surprise to folks that don't keep up (most people, I know, but I tend to keep up with this stuff and like to buy and hold land ahead of development). Bishop Arts for example has been a 3 decade overnight success, similar story with other areas you mentioned. Many of those areas I felt like they took way longer than they should have to get developed, and it's because all money goes north to the burbs. Uptown is about as far south as most money is willing to go. Design District, Deep Ellum, Cedars are proximity plays after Uptown got kind of expensive.
I don't really do much nightlife stuff. But about 10-15 years ago, Uptown was like the young professional/college kid place to be. Many of those folks moved to the burbs after a certain age. But many stayed. Now the prices are high, it seems like it's more full of those same folks that never married, never had kids, etc and just happen to be 10-15 years older. I think it still has the reputation but realistically, younger crowds (<30 or so) don't seem to spend much time there anymore in favor of Deep Ellum, etc.