We should probably start by saying that tubeless tires are a style of clincher tire before the pedants get to us. The biggest difference in road bike tires is if they are tubular or clincher. Tubulars are a one-piece style tire.
Wider tires have often been said to be slower than narrower tires, and this is one of those cycling myths that is now being put to bed. The thinking was that wider tires would have a wider contact patch with the ground than which narrower tires do.