I have just (today) taken delivery of a new mouse, the Logitech MX Ergo.
I had an MX Master (gen 1) but it had a button fail and, since the free spin/click switch had also failed some time before, I decided to replace it. I have had a wrist injury following an accident a couple of years ago and the idea of a less horizontal mouse appealed as they are supposed to be better for that.
Vertical mice are good but the sensors aren't usually the best. The MX Ergo had some good reviews and, despite never having had a trackball mouse, I thought I would try it when I saw it for sale at $119 instead of the $200+ it is often sold at.
So far, now it is set up, it seems much more comfortable. I have not yet trained myself not to move it physically - although I am sure that will come after a day or two - and it is quite customisable in terms of the functions you can set for each button.
I will update in a day or two!