>>533899352
Sometimes, "right clicking" is not an option! When I was a kid, we'd sometimes play FPS games with "tractor controls" to mess around: using left and right arrow keys to turn around, no strafing, having to press a key on the keyboard to shoot, and so on. FPSes had that as an option all the way into 2000s. Computer mice became a thing significantly later than keyboards, and were seen by many users as superfluous. So, that whole genre of games wasn't really expected to take off, but then ended up helping promote the mouse.
And even outside of games, you might be surprised how much you can do on modern Windows without a mouse just by using the arrow keys, Shift, Alt and Tab on top of the usual shortcuts!