It was actually developed for ease of use when writing with a fountain pen. With a pencil or a ballpoint pen, I think printing is just as fast. I actually challenged one of my cursive using friends to a race once, and I won.

That being said, I'm old enough to have been taught how to handwrite (as opposed to print-style characters), but I wasn't taught cursive. I was taught an alternative that was faster and more legible. I still abandoned it 5 years later when I was approaching high school. Legibility of my writing was more important than speed. And I quickly discovered that printing wasn't actually slower. All I handwrite these days is my signature, and it's honestly just an aesthetically pleasing scrawl.