I tried an MX Master 3 and 2S, I also have the MX Ergo trackball mouse and the Logitech vertical mouse. The vertical mouse is what I ended up with, but for years I would switch mice, switch between several mice within a day, switch hands - and they were all half-measures that just kind of delayed the "degeneration". The issue, it would seem, was not the mouse or overusing the mouse. The issue seems to have come from my shoulder area (Thoracic Outlet Syndrome aka TOS / Pec. Minor Syndrome), which a vertical mouse will uniquely address as it allows your shoulder to be less interiorly-rotated than a standard mouse, even a trackball mouse that is not vertical.
I remember reading a Medium article a while ago about a software engineer who described how he addressed his "RSI", which I suspect was just TOS - he switched to an ergonomic keyboard and vertical mouse, which over a period of MANY MONTHS more or less resolved his RSI. He talked about how he still has to be careful and take breaks often. I really think, especially considering his age (20s), he could have kept the mouse and keyboard he had, if he just engaged in posture-correcting shoulder stretches and strength exercises.