Interesting to see this come up. I've given guitar lessons to a few people starting out and always use this argument (and the "right handed world") for why they should play a right handed guitar even if they're left handed.

Lots of skills not only ambidextrous in nature but are anatomically unnatural when first learning. Not too mention limiting yourself to left handed instrument can become a nightmare when looking for a new guitar or something.

Just for reference, I group up left handed (my father is left handed/ambidextrous). I remember having to use special grips in kindergarten to learn to write left handed, then from grade 1 on I always heard how bad my handwriting was.

Strangely, this was in the early 00s. Reading some other comments, it sounds like this fell out of fashion in most places well before this. Looking back though, aside from poor handwriting (eventually got better with cursive) it's honestly made my life easier going forward.