In true wilderness untouched by man or by man made gear and equipment, pliers have few uses. Mainly removing quils, thorns and splinters, and perhaps cracking nuts.

Most of us venturing into the wildnernes will however have a fair bit of modern gear and equipment, and pliers are useful for all sorts of repairs and improvisations.
Bending or straightening hooks and D rings, holding items in or near a fire, unsticking zippers and pulling out nails come to mind.
Very useful for fire lighting IME as the pliers permit of tinder etc being placed exactly where required without burning the fingers.
Also useful for crunching up small sticks or pieces of wood into very small, matchstick sized pieces for fire lighting.
Just yesterday I used the pliers of a Leatherman tool to open a ring pull can of food from which the ring had come off. This was indoors, but could just as well happened in the outdoors. Opening the can with only a knife would not have been easy with some risk of damage to both knbife and user.

Plier based multi tools are of course very useful in the built enviroment, and the best survival tool is the one that you have with you. He who is used to ECDing a Leatherman tool or equivalent will probably have it with him "by default" in the great outdoors.

On a trip some years ago I noticed my whitewater rafting guide had a Gerber Shorty knife, but next to it a small plain pair of pliars in a belt pouch. When he didn't want to cut a soggy knotted line, the pliars really helped pull the knot loose. He was a 100+ trip guide at that time, and said that he would never go out without his pliars handy.

A fair number of people forgo multitools on the theory they are not very good tools.

I used to carry a MT with me on service calls. over time I switched to needle nose pliers, wire cutters, and a multi bit screwdriver. now I leave the tools at home and let the plant electrician cart the tools and do the work for me.

Much cheaper and far more effective than a MT.

The extra weight is an issue in a pack though. But still, a fair number of people carry a small pair of vise grips and leave the MT at home.

The one tool I have used above all else on a MT is the pliers. But, it is not a very good set of pliers, so I can understand why some would go to a vise grip. I have seriously considered doing so.

From time immemorial, I have carried a multitool or its predecessor, the SAK, as EDC. When I knew I was faced with a task that required "real" tools, I carried them. Tool-kits-on-a-knife are great when you inadvertently run into a situation that requires a screw to be tightened, or a widget adjusted. Then it saves time and steps. But if you are going to be wrenching for a long time, get the real McCoy.

Frankly, I don't feel I am fully functional without my MT handy. Of course there are days when I never used it, but there are also plenty of times when it really comes in handy. Like so many things we discuss, it all depends on the specific situation and circumstances

The pliers on a MT aren't as good as even a $3 pair of Wal-Mart pliers but they're a lot more compact, and often sufficient for the task. I've been surprised at all the times I've used them in the woods. If nothing else they're a great pot grabber that also carries a screwdriver, knife, file and saw.

I carry my Leatherman as EDC because I may need it BEFORE I get to the woods. Plus, it is good for gear repair, etc. Keep a Wenger SAK in my pocket too.

I've also quit carrying my full-sized Leatherman in favor of the very small, very light PS. It has a small pliers if I need to fix something on my backpack or fishing pole and a scissors to cut fishing line. I can use (and have) my knife in the screw head in a pinch.

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