There is probably some value in being able to read the original founding documents of your government. In the United States those are written in cursive.
Reading and writing are two different skills. I can read a variety of different calligraphy styles, for example, but would be hard-pressed to reproduce them well.
Normally the way people learn to read cursive is by having some exposure to writing it. Most kids who haven't learned to write cursive can't read it. But I agree with your overall point. Kids could probably learn to read cursive with significantly less effort than what is required to write it.
I guess we should all start writing those s's that look like lowercase f's again then. Or people in the UK need to start getting fluent in Middle English to read the Magna Carta
Why? I mean, if anyone really wants to read the originals, they can learn cursive then. But why aren't transcripts enough for the average person?