It's all just the progress in technical/mechanical aids to the illiterate.

Pittman shorthand was universally accepted as being faster and more legible than the Gregg that replaced it, but Pittman relied on line width differences, applied by pressing down to spread the point on a quill or steel nib.

The invasion of decent pencils, and ultimately the "ball point pen" made it impossible to write legible Pittman, so Gregg became dominant.

Development of the typewriter (and the "stenotype") made much manual shorthand a dying art, although it did persist at least into the 60s in some places.

I took lots of engineering notes in Gregg (somewhat crude, since I only spent one weekend learning it) when some nosy person tried to read what I was writing over my shoulder in meetings. It always worked.

As late as the mid '70s, I "accidentally" found some "interesting comments" about the boss in one secretary's Gregg book (apologies for the accident, and agreements on confidentiality properly executed), but by that time several of the better "assistants" could type faster than anyone could talk, so they just made the originals on the spot.

I do persist in using cursive when I write checks, as I refuse to use a debit card. Those I know personally who use debit cards spend a whole lot more time and effort trying to balance their books (if they bother at all) than I do writing the checks and keeping the books, and often spend longer in the checkout line trying to "swipe it" so the reader can figure out who they are than it takes me to do a paper check.

As to the earlier comment: Whoever invented cursive writing despised left-handed people more than anyone except the people who design repeating firearms. one can always do it like DaVinci and just write mirror image cursive right to left. If you only use one side, the prof can flip it over and read it through the paper.

And left handed firearms actualy are fairly easily available in many popular models (for a few bucks more).

John