The problem occurs in Unity 2018 and is still not fixed in Unity 2021.3.5f1.
I’m running an empty scene and I just move my mouse rapidly and the profier shows high hitches.
I’m using Logitech GPW2 and the higher the pooling rate is, the higher the hitches go.
The Unity version of the screen record is Unity 2021.3.5f1:
I found three issues on this topic and there are other devices which have the same issue.
However, two of them are marked as FIXED, which makes me quite confused:
Can you please try with a built player? I fixed issues related to that in player code, and we were fixing editor UI performance issues separately, though I think editor is still might be impacted by high refresh rate mice.