I use a Wacom Intuos Pro with a mixture of Paint Tool SAI and Photoshop CS6 (SAI for the actual drawing, Photoshop for stuff like text, panelling, file formatting, etc.)
I've tinkered around a bit with Clip Studio Paint but I'm still learning the program. So far, I like it, but SAI is still my strongest tool so I'm sorta just practicing with Clip Studio Paint on the side.
It's hard, but doable. I used to be pretty good with the mouse before I got my first drawing tablet when I was like, 14. Back then I used RateMyDrawings (an old drawing website that has honestly seen much better days) and my mouse. Made some pretty good drawings with it at the time.
Computer mice are also super good for doing pixel art with, as pixel art doesn't necessarily require pressure-sensitivity like most styles and mediums do.