I'm using the U3219Q at 1:1 resolution (so 3800px wide) on BigSur and Monterey, and some display text is sharp at the beginning and end of the text block, but fuzzy in the middle. It's like there's an aliasing going on, where a text block that would be natively 100 px wide is shown at 99px or 100px.

It was better on previous versions, I think Mojave was the last good one.