Why F1 cars have smooth tyres?(30 words)
In dry conditions ‘slick’ tyres without tread give better performance. You have more rubber in contact with the track surface and the tread block is more mechanically stable.
The only reason that road tyres have a grooved tread pattern is to disperse water and reduce the risk of aquaplaning. Most racing formulae have the option to use different tyres for wet conditions, either by quick wheel changes during the race by suspending the race in bad weather or just by starting on an appropriate tyre if it is obviously going to be a wet race.
Having that some racing series do run on all weather tyres all the time for reasons of simplicity and cost control.