Hate to disappoint, but even Ultrasharp isn't spared the post-pandemic QC of other brands. At one point I tried to get a U2717D, twice - both returned for horrid uniformity. Dell makes no guarantee as to uniformity on these panels, but they do have a relatively stringent dead pixel policy iirc (take note, MSI and Gigabyte).
I do have a U2515H across the pond though, and it is a flawless monitor. I have a S2721DGF now and it's good, gotten better with time - its uniformity issues are less to do with Dell and more inherent to the LG 27GL850 panel it's using.
That said, it doesn't change that Dell is head and shoulders above everyone else when it comes to warranty, support and return policy on its higher end monitors (Ultrasharp and higher end gaming monitors have the same premium warranty and returns). And in a panel market where you're more likely to repeatedly play the try-it-and-return-it lottery than get a good panel, that return policy is worth more than anything else. Normally only Amazon and brick-and-mortar stores are that generous.
To get guaranteed uniformity (or at least better, with software to mitigate it), you need to at least step up to a pro-line BenQ (SW270C, SW271) or high end Eizo. Think the top Asus ProArts too maybe. All of which are Adobe RGB panels, cost as much as a GPU, and aimed at pros with colour accuracy needs.
The Ultrasharps usually have actually good accuracy out of the box, and respond well to proper calibration as well.
Benq SW line is garbage. They get "aceptable" color uniformity with agressive uniformity correction that drops contrast bellow 700:1 at D65 white (user cannot turn it off).
Eizo gets perfect color uniformity with no compensation, and very good brightness uniformity with uniformity compensation and contrast drop.
The outsiders in my generalization are CS2740 and SW271C which have poorer contrast than other CS models, although Eizo model does better than Benq... and the fact that Eizo software actually works.
Asus ProArt AdobeRGB widegamuts were and are the worst models in the market with extremely poor non correctable color uniformity, and uniformity compensation only corrected brightness. Also their HW calibration software sucks, a total failure. The outsider in this generalization is Asus PA32UCG which seems to have (a high chance in QC lottery to) an astonishing quality, contrast and color uniformity... although I have my fears about Asus software and their support.
Like Dell in the past, Asus mixes in the ProArt line very good sRGB IPS with their AdobeRGB garbage, hence "ProArt" line means a lot of things and may mislead public if we label the whole line as a block.
Also you are making a comparison with office grade from Dell (sRGB or P3), "U", the models in this article, instead with Dell "UP" line (AdobeRGB and P3) which should be equivalent to Benq SW / Asus ProArt (AdobeRGB widegamut) lines. UP line have uniformity compnesation. It's true that 10 years ago "U" line was both office and photo edition line with good sRGB IPS and widegamut (AdobeRGB type) IPS, like current Asus ProArt.
A final note. Panels are not AdobeRGB or sRGB or P3 (unless you go to OLED AMOLED domain). Display colorspace is given by the LED used in rear backlight, by its spectral power distribution.
