I'll belatedly put your link up there too. Thanks!

Probably 0% reported, considering the negative views towards left-handedness at the time.

I think it's genetic, and probably a spectrum. My mom's family has a few lefties, and a number of righties that play traditionally left handed positions in team sports.

I think I was destined to be ambidextrous (well, ambiUNdextrous!) as I used to write the left side of the page with my left and switch over, and you'd be hard-pressed to spot where the change had happened. If teachers encouraged me to pick a side, the quality of my writing dropped on the other side of the page. I only started to favour the right when my eyes started going “properly funny” (I have a couple of faults there which interact in interesting ways) which meant to be comfortable I tended to turn what I was writing on clockwise (which made writing with the left much less comfortable/practical).

> I was a very awkward and uncoordinated kid

Same. And no different as an adult! (even worse now I get recurring vertigo…)

In my case I think it is largely due to my eyes though: my assumption being that because the faults with them changed a lot at the same time I was developing & growing generally, my body/brain were a bit hindered wrt working out the hand-eye coordination and general proprioception businesses.

One interesting note is that mix-handedness is more common than you might think, and it can confer an advantage in some sports and other areas just as full ambidextrousness can: https://en.wikipedia.org/wiki/Cross-dominance

I could see (pun intended) feeling at loose ends trying to do eye driven tasks opposite handed, especially if you are naturally left-handed.

I definitely agree tho, in my youth I thought science and rational thought would be spread by enhanced worldwide communications but should have known all that would be spread was the natural and inevitable state of human degeneracy.

This is untrue and actually uncommon. Not every instrument is a guitar. Left handed cello players don't string their instrument upside-down. They play it right handed.

On the guitar, the left hand is doing a lot more than just pressing on strings: chords, slides, bends, tapping as in hammer-ons/pull-offs, natural harmonics, even muting strings in some techniques (see Stevie Ray Vaughan’s style).

The right hand is also doing more than just strumming or picking: two-handed tapping, artificial harmonics, palm muting, using the whammy bar to produce vibrato or whole-chord bends.

There are also techniques like sweep picking which require very precise coordination between both hands.

Same goes for fretless string instruments: playing long notes by drawing the bow over the strings (legato) is the bread and butter of bowed instruments like the violin and the cello, but they can also be played with short stabs of the bow (staccato) or by picking the strings with the fingers of the right hand (pizzicato), among others. Vibrato and slides are played using the left hand, simply by moving the finger up and down the string.