A mouse or trackpad is a 2D input device. Unless you have a 2D input problem (dragging nodes in a graph, drawing a free form curve, selecting a point on a map…) then it was never the right tool to begin with.
Navigating discrete UI elements or making simple UI actions of the kind that can be mapped to keyboard input - that’s easily doable with a keyboard. Occasionally it’s just a tad harder with keyboard than with mouse (web pages are notoriously useless with keyboard) but it’s possible.
I wouldn’t last a day without going crazy without a mouse though. People who say they have gone mouseless also seem to argue they have zero 2D input and basically use text and ignore all other workloads. That’s not exactly solving the problem (not that I think it can be solved any better than just using a mouse!)
Sort of (depends on terminology): A form is a set of controls laid out in 2D. But they are ordered and discrete so you can just ignore their positioning in x,y and instead navigate in their order instead (e.g tabbing through controls) making it a 1D input!
By “2D input” in this context I mean input where there isn’t also such a navigation option and you must input one or more coordinates and there is no way to enter the coordinates as numbers. For example the input surface (image) in a drawing program like Microsoft paint.
I think you're equating "random" with keyboard and "sequential" with mouse, but I also think of keyboard as "serial" and keyboard + mouse as "parallel".
yes. But text UIs are, arguably, infinite-dimensional (because language is). Thus a 2D input problem is a severely limited particular case, that allows for very specific and useful optimizations helped by a mouse, pad or trackball.
Navigating discrete UI elements or making simple UI actions of the kind that can be mapped to keyboard input - that’s easily doable with a keyboard. Occasionally it’s just a tad harder with keyboard than with mouse (web pages are notoriously useless with keyboard) but it’s possible.
I wouldn’t last a day without going crazy without a mouse though. People who say they have gone mouseless also seem to argue they have zero 2D input and basically use text and ignore all other workloads. That’s not exactly solving the problem (not that I think it can be solved any better than just using a mouse!)