I like zip ties for some things. For one, they stay and do not quickly lose strength, even in a lousy environment. Two, you can get them tight, and once they are tight, they do not slacken. And for somethings they are relatively quick, compared with the right knot. For instance, a couple of the garbage zip ties could do what a tying turkshead could do and save you a few hours.
However, and I am not putting down the zip ties or anyone, but
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.
this tells me that knot-tying is an area in which a lot of people could improve their proficiency. I cannot imagine the time it would take me to work with zip ties and get that anything like a calf's legs tied, but a piece of line it would take nothing flat.