On ours we have an "eye" sewn at the bow end that goes under and then over the cleat centered just aft of the bow. We then go back to cleats about seven feet from the stern and tie them off there.
1 - are you willing to trust your life to the webbing (my answer is yes)
2 - are you willing to trust your life to your sewing of the "eye" - again, my answer is yes.
And for that price - I can replace them just about as often I we want. And, I bet I could lift a truck with the webbing. - but that is just a guess.
UV degradation?? Ours are inside the cabin unless rigged. In most cases they don't get rigged because in most cases we stay put if we are going to need jack lines. Always rigged and used for night sailing and we have found that there is not a lot of UV degradation to the jack lines at night.
Irwin Citation 34