One day Homer was doing a reading of The Illiad at an open mic night, and Socrates came up to him and said, “Dude, this would be so much better with a little musical accompaniment.”
The two thought on it a bit, and decided they could stretch some strings and pluck at them and the lyre was born.
At least I’m pretty sure that’s how it went. Maybe don’t quote me.
Over the centuries, the lyre evolved, but stayed true to it’s early use as an instrument that was primarily plucked with the fingers. Since this was the main interface to the instrument, it was natural that most held the lyre with their left hand and plucked with their right.
Over time, stringed instruments evolved. Necks were added, we got violins. Later frets and in the last couple of hundred years the modern guitar. But no where along the way in this gradual evolution, did the right-handed folks think to flip the instrument - which is unfortunate for them because for most modern guitar styles, the left hand does most of the work and requires the most coordination and dexterity.
If you are a righty and have learned to play guitar, you likely struggled early on teaching your left hand to do those chords. Obviously, this can be overcome, but if I were a righty learning to play today, I’d consider learning on a lefty guitar.
I’m a lefty and have always been very glad I choose to learn on right-handed instruments. It always seemed a lot more natural.