Surface irregularities (bumpiness) are the reason why lower pressure tyres are now preferred on bikes. The idea is that a very rigid tyre will deflect the bike and rider up and down which wastes some energy/momentum as well as fatiguing the rider, whereas a lower pressure tyre can absorb those irregularities and "roll-over" the bumps. This is part of the reason that recent thinking has moved from skinny high pressure tyres, to wider medium pressure tyres. (Wider tyres will tend to roll quicker than a thin tyre at the same pressure - something to do with how the contact patch deforms the rubber).

However, cycling tracks are designed to be very smooth which is why high pressure tyres are still used there.