You usually have to lift to increase tire diameter so the tires dont rub the fender. Ive been looking at 3" lift kits so i can lift my truck and fit 35's vs 33's. Without the lift the tires will rub the fender liners when turning.

To save people from getting crushed when they don't know how to change a tire. (pic8.co)

Lifting the vehicle also raises the center of gravity, so they are more likely to tip over. Very dangerous if you lose control, especially on ice.

Tiny penis stuff. I don't get it either bro

Sometimes you can be a real faggot.

In light powder snow, lifting the truck will allow you to drive in deeper snow. Assuming you have a solid axle, dragging the diff through the snow is possible, but once the snow is up to the frame you'll get bogged down. An independent suspension, like most medium pickups and suv will work even better. This won't work so much in the wet heavy snow, but the type of snow you get is very dependent on location. Water crossings are also aided by a pure lift.

That being said, 99% of lifts are purely cosmetic. When the owner doesn't do stuff like axle breathers and longer brake lines it becomes a pretty good liability. Also on independent suspensions it will usually exceed the angles for the cv axles and wear down much quicker.

Lift kits also increase your approach angle and departure angle allowing you to climb steeper hills without hitting your bumpers.

I lifted my GMT400 with a 3" suspension lift so I could fit 33" mud tires on it. That truck is great for getting my livestock trailer into the pasture so I can load up my cows.

https://pic8.co/sh/vfwUTv.jpg

That curb at the mall is tall

Tire clearance, suspension articulation, attack angle, body lifts help with engine swap/header clearances too.

The lift allows crossing deeper water, deeper mud, negotiating larger obstacles, installing bigger engines, changing over to 4 point suspension (more articulation).

The biggest reason for 80% of truck lifts, "it looks cool".