Still, comparing 5K and 4K is still comparing apples and oranges. The point is, 4K will never be as good as 5K on macOS because of how macOS handles scaling, but looks fine on Windows. Since I spend a good amount of time on the computer for productivity, 1440p scaling on 4K will never give the best experience compared to 5K. Also, you have high end 4K monitors costing as much as a 5K monitor like the UP2720Q with simular color and cost, but vastly inferior resolution.I don't think it is. It's taking that one aspect that the ASD does better out of the equation and then putting the rest of its features in competition with the more varied 4K market. If you value 5K over anything else, then your options are just very limited and the ASD is just as good (and bad) as most everything else with 5K res.
I'll gladly compromise by going from 5K -> 4K but gaining high refresh rate options and a lot lower price in the process. 4K to me is sharp enough and if I want more desktop space I can pile on more displays on my desk while still being way under the cost of one ASD.
Since the ASD was hard to get a hold of since people are buying them up and the growing popularity of Apple Silicon Macs, I do hope there are more manufacturers that would build 5K displays that work better on macOS along with more affordable options. The options that are currently available that work best with Macs are limited and the 4K option is just compromised and in my opinion, does not give the best experience.