One thing about using zip ties vs. tying line, when I am holding something that I need to bind together in one hand, I can fairly easily put a zip tie on the bind with the other, whereas I am seldom able to tie a line with only one hand. It can be done, but it is awful hard most of the time. Hanging on a tower while holding down a loose cable, I can grab a zip tie, wrap it around the cable and the tie-down brace, and push the tip through the eyelet, using just one hand the whole time. I am also able to do zip-ties when my hands are so cold they are fairly numb, when I have been unable to tie a knot in a line without great difficulty.

Maybe there's folks out there who are better at line tying than I am, but the dozen or so field techs I've worked with would agree zip ties are a lot easier to deploy than line as a fastener out in the field. Calf roping might be a good place where tying a line could be preferable to using a zip-tie, if you know what you are doing. I reckon there's a whole lot more folks out there that could bind up three legs with a proper sized zip tie than could work out a three wrap hitch knot and expect it to hold, without any practice.