Natural fibers like jute and manila are obsolete for rope and cordage. They degrade more quickly and unpredictably than synthetics and in every respect are inferior.

I'll bet the force exerted on a tarp in high winds can easily snap jute in the size range of paracord. Actually, there are now better materials than paracord for light cordage suitable for shelters and similar. I've got some stuff that is one half the size and twice the strength of 550 - "ironwire" is what the supplier calls it. It's actually pretty hard to beat braided mason's twice for most uses.