I think the problem with incentivizing anything in a centralized way is that, in the short term at least¹, it's at best a zero sum game: one person's incentive is another's disincentive. Meaning, I don't think builders would vote for your tax credit plan unless they were somehow incentivized too. I also don't think this is a problem to be solved with incentives anymore than we could solve gun violence with incentivizes to wear bulletproof shirts. I think it's a real-estate-is-a-speculative-investment problem, an already-subsidized-thing problem, a holding-a-crappy-building-is-less-crappy-than-holding-dollars problem, and/or even-cheap-things-are-expensive-when-other-people-have-too-many-dollars-and-we-have-very-few problem.

They're demolishing and will soon rebuild Austin's primary conference center. The building is a couple decades old at most. It wasn't in disrepair and didn't look bad in any serious way. They claim they're replacing it to increase its size, but I think it's also because the design fell out of fashion. And, instead of replacing it with a timeless design, they are replacing it with another fashionable structure.

I've noticed this trend with most of Austin's architecture. I think it's part of what makes Austin feel weird. Most things are designed to be very trendy and are built cheap and fast in an attempt to catch coastal dollars as they blow through our humid desert. We end up with a mishmash of buildings where the only thing they have in common after a decade or so is nonsense.

Here's the new conference center: https://unconventionalatx.com/overview/. I would wager they'll demolish and rebuild it again in 20 years.