Indeed, but it must be quite annoying.
I imagine having to use my mouse with my left hand, would be really weird, not just because I’m not used to it, but because this is not my main hand.
I grew up using it like that. So it’s not weird at all.
You also don’t feel weird using cutlery in both hands, do you?
I learned to do some basic things like that with my left hand after developing chronic tendinitis in my right. Brushing my teeth or eating, for example. It’d be surprisingly easy if it was just moving the cursor, but it’s so ingrained that the index finger does the main clicking and the middle finger the secondary key that I couldn’t get used to it.