When going through the effort to re-learn how to write, why would one learn this rather than one of the more logical/easy shorthand systems?
(To clarify, I mean in this day and age! I would understand if one needed to send 300 letters a day to a non-shorthand reader.)
Here's a nice article on some shorthands: https://blog.zdsmith.com/series/shorthands.html
I would strongly disagree.
Shorthand is (hopefully lossless) compression technique.
Cursive is a font optimized for continuous use by the human hand and a stylus, leveraging keeping the stylus point on the page between letters of the same word.
It's comparing 7-Zip to Arial.
At their core, sensible shorthand systems are just another alphabet of shapes that are easy to form and string together.
They add various aabreviations and common short forms on top of that, but one easily gets something like 50 % of the benefit by only using them as an alternative alphabet.
As the sibling says, shorthand is a very different thing. Cursive seems much more a way to write with fewer finger movements. That is about it.
I'm tempted to say it is also about fewer pickups of the pen, but I think that is largely the same thing. Many of the finger movements you do when writing otherwise will be to pick the pen off the page.
The shorthand systems are mostly designed to be transcribed by the writer or someone very familiar with the writer's particular style, preferably while the information is still fresh in someone's mind to resolve ambiguity. Shorthand is mostly not a great system for long term information storage and it's not easy to quickly skim documents written in shorthand.
I don't know what you'd consider the more "logical" systems - there are only a few non-machine English shorthand systems with any degree of popularity. My own experience with Teeeline shorthand (which is a bit easier to learn, and I'm by no means good) is that I simply can't read quickly because I don't get much reading practice. Think about it: most of us read much more than we write. With shorthand, I only end up transcribing what I myself have written. So I'm slow at it.
No one is stopping you from using muscular movement to speed up your shorthand even more.
If you use finger movement for shorthand you still have a 30 minute writing limit before you start getting hand cramps and carpal tunnel syndrome after a few years.