They are not only important for wet conditions. People tend to lose control on wet surfaces because the water acts as a lubricant, causing the wheel to slide more easily. A tire with 'better' tread will slide less than a tire with 'worse' tread.
The information given in the question is not sufficient to answer it. Information on the road conditions (wet or dry) and the state of the tyre treads is also important - but unknown.
For better traction.
It is 0.95
because it helps the car when driving
If the treads lack definition and/or if the car "pulls" to the left or right.
On dry, firm roads, pretty much nothing. Treads are there to deal with water and soft surfaces. Modern treads are also designed to help avoid hydroplaning on very wet roadway, without treads a car would very easily hydroplane (completely losing contact with the roadway when there is even just a little water over the roadway, causing the car to 'float' with no traction whatsoever).
They are wide to gain maximum traction and bald because they are only used on dry tracks. In wet weather, racing tires with treads are used.
the tread is part of the tyre that is supposed to touch the ground
When obtaining a loan with a car as security, the terms and conditions typically include providing proof of ownership of the car, agreeing to allow the lender to repossess the car if the loan is not repaid, and paying interest on the loan amount. It is important to carefully read and understand all the terms and conditions before agreeing to the loan.
The grooves (treads) are there to give better grip (like car tyres) on wet and slippery surfaces.
You can use it until it reaches the wear indicators which are located between the treads.
Less grip on the road surface. Bald tires are also more likely to hydroplane.