The Switch 2 Joy-Cons promise more functionality than the average controller. However, not all testers who have experimented with the new mouse mode are optimistic. Some testers believe poor ergonomics overshadow their versatility.https://www.notebookcheck.net/Nintendo-Switch-2-Joy-Con-mouse-mode-described-as-an-ergonomic-nightmare-by-some-testers.997938.0.html
It's because we haven't use that muscle before.