Cracks on a car tire are a huge problem. The edges of the crack rub on each other and cause a lot of heat and will cause the tire to fail monstrously at speed.

Bike tires do not share this problem because of the lower weights and the speeds.

Good rubber grips well. Thick rubber will (marginally) resist flats better. New rubber looks good. Other than that, ride the thing if it is not bulging out anywhere.

jim