Because of the type of terrain that mountain bikes have to travel across, IE, gravel, mud, loose earth and steep climbs/descents on the previous surface conditions, mountain bike tyres need as much grip as possible, hence the deep tread and width on the tyres.
I assume you are referring to the tread. High grip will have a more aggressive tread design used in off-road conditions or in deep snow. They are called off-road tires or snow tires. The difference is in the tread design.
Deep tread added to snow tires.
The treads are generally about a half inch deep. To check for safe tread depth use a penny, if you can't see the top of the head of Abe Lincoln then the tread is fine.
It's road noise caused by deep tread depth. This is more common with off road type tires with agrressive tread design.
The best fat bike winter tires for riding in snowy conditions are typically studded tires with aggressive tread patterns to provide traction on icy and snowy surfaces. Look for tires specifically designed for winter riding with deep lugs and durable construction to handle the harsh conditions. Some popular options include the Schwalbe Ice Spiker Pro and the 45NRTH Dillinger.
When you are traveling along and the tires are unable to move the water on the road through the tread and dissipate it the tire will lift off the road. This is hydroplaning. Normally this is caused by tires that are worn out and need replacing. But if the water on the road is deep enough a new tire will hydroplane.
Slow down and avoid driving into deep water covering the road. Replace worn tires that have less than 4/32" of tread wear left.
The tread depth of Super Swamper Bogger tires is 25/32 making them very good for use in deep snow or muddy conditions. They normally cost around three hundred and fifty dollars.
Smooth tyres have less frictional grip on the road surface, and will slide further that a deep tread tyre.
The best electric bicycle tires for off-road adventures are typically wider, with deep treads for better traction and stability on rough terrain. Look for tires specifically designed for off-road use, such as those with aggressive tread patterns and durable construction. Brands like Maxxis, Schwalbe, and Continental are popular choices for off-road electric bike tires.
DOT minimums are 2/32ds for trailer tires and drive tires, and 4/32nds for steer tires. New from the factory, it varies between tires. Drive tires may come new at up to 28/32nds, while steer tires tend to be closer to 19/32nds new.
"Check the tread by using the "penny test." Take a penny, and place it upside down with Lincoln facing you in the center of the tread (at the thickest part of the tire).If you can see the very top of Lincoln's head or the copper above it, replace the tires immediately.If Lincoln's hair on the top of his head is partially visible, it is time to go shopping for tires.If you cannot see the hair on the top of his head (if the coin is inserted enough that the tire tread is at least as deep as Lincoln's forehead), your tires do not need replacing yet. " ~ WikiHow