Penmanship is a huge factor when applying for jobs, especially in office jobs. So working on cursive writing at a young age will help with penmanship later on. Say an employer has to choose between two people applying for a job, both have nearly stellar resumes and both would be perfect for the job, but one has sloppy handwriting that isn't eligible, and the other has clean, cursive handwriting. In the end, the employer will most likely hire the one with great penmanship.
Cursive isn't detrimental in any way, it makes your writing look nice and smooth, and it's efficient to use. There's no reason not to learn cursive unless you're lazy. Personally my handwriting is bad so my cursive looks worse than most, but I think the average person should still learn it.
When I was in third grade, my teacher insisted on teaching us cursive. I'm n high school now and I greatly appreciate learning cursive. It makes writing a lot faster and it looks good and it's very easy to read. Cursive looks nice on cards, papers, or rough drafts for an essay.
Since I have graduated high school...Actually middle school, I have never used cursive handwriting in my everyday life, other than when I use my signature. Cursive is easy to read when it is typed up in a computer document, but when it is physically written by human hands...Nine times out of ten, It is the most illegible writing I have ever seen. I also have never heard of someone not being hired because they couldn't write in cursive..Never in all my days. Why not use technology and type up a document in cursive writing?
It is quicker and easier to write in print.