There’s no list per-se. The MacBook Pro (2021 and later) is listed as supported. The M3 Pro and M3 Max are not listed as only supporting 60Hz while the M3 and M1 Pro are.
Dell U4025QW: 5120 x 2160 = 11,059,200 vs Apple Studio Display XDR: 5120 x 2880 = 14,745,600
So your display has 25% less pixels.
I had no idea what it was for the longest time. As it turns out, macOS frequently enables it even when it’s unnecessary, and without any way to override.