Okay, too late to edit, but I decided to take a look. The latest version of P4V actually is using Qt6, so I guess I have to stand somewhat corrected.

I'm just bitter about a couple of apps I use that are all permanently stuck on Qt4 where the vendor seems to have zero intention of caring to ever update them to a newer version of Qt. And ever since getting a HiDPI display, this has been continuously irritating me.