I think cursive was designed for feather dipped ink pens so they didn't have to be lifted because that often causes blobs.
It's also something you can learn easily on the side.
I think it's primary benefit is if it's taught to kids, it helps them develop fine motor skills.
We may see a decline in art drawing abilities due to this. (Among other issues that would contribute to this).
Poorer surgeons.
Loss of quality Craftsmanship in many detail oriented fields.
We learn skills like this better as kids.
That's my only real argument why it should still be taught. Kids don't really learn fine motor tool manipulation skills like this in their other activities.
Human hands are one of our greatest strengths. Shame to not develop this better in kids.