Most Millennials I know who are technical absolutely love mice because they grew up using them, and most of them have extensive PC gaming experience to boot.
I’m the Linux/CLI junky among them and even I don’t find mousing cumbersome—to use someone else’s words, it’s an amazing, first class input device. Same goes for trackballs. By comparison touchscreens are a joke, there’s no depth of input like with a mouse(RMB,LMB,etc) and every action requires large physical movements.
I’m used to seeing people fly through menus with a mouse at speeds people here expect to only to see from keyboard shortcuts. Just because mousing is cumbersome for you, doesn’t means it’s universally true at all. I know keyboard shortcuts are fast, but it’s a lot to memorize compared to menus which typically have the same basic order. File|Edit|View|...|Help
Interesting! I am definitely in your first group. Born in the 90s, grew up using a mouse and playing mouse driven PC games, yet I far, far prefer the concise precision of a keyboard.
I guess it just depends on what the program requires of your inputs. When it comes to software development, window switching and maneuvering around websites, keyboards are precise and rapid, where the mouse can only do one thing at a time before needing to travel to the next input.
The other important part about ditching the mouse, is that when you're predominantly typing and using both hands on the keyboard, switching over to the mouse takes a non-trivial amount of time. You have to move your hand over there, figure out where the cursor is on the screen, then do what you need to do with it. When you're doing it hundreds of times a day, it adds up.
I grew up with a mouse too and am excellent with it. I was born in the 90’s for reference. However recently on the job I have learned to use keyboard to navigate mainframe menus and editors and it’s very nice. While I don’t find a mouse bad at all, it is noticeably less efficient in some key use cases. Many productivity tools could benefit from a focus on keyboard interfacing.