Using shift + scroll wheel to horizontally scroll in a UI. Whenever I see my project manager going all the way to the bottom of the application and dragging the scrollbars to move horizontally it just kills me a bit inside haha.
I'm just glad that KDE now has an option to disable pasting using the middle mouse button (mousewheel). Only available on Wayland though - AFAIK this behaviour is deeply rooted in X11 and it's not easy to disable it.
I see. When using X11, I was using xinput to set MMB scrolling, but at that time, it had the problem of activating the MMB paste function, if I didn't click and hold properly.
Over time, my habits changed and I kinda stopped using it. But maybe I'll try again once it comes in Plasma 6.2 (it's actually in beta rn)
Turns out I just had to enable the auto scroll option in Firefox itself. Looks like I never had it on in Windows before, but the OS took care of it there.
I had a Logitech MX Ergo mouse that allegedly had horizontal scrolling. The wheel could tilt left and right which clicked like a button, and the screen would scroll very very slightly to the side. Worst trackball I've ever had.
Just before they stopped making PCs, I saw an IBM computer with a mouse that had one of their Thinkpad clits instead of a scroll wheel. So a proper XY input. I think a blackberry ball would work too.