In the anime, stupid kids bring their pokemon to the pokemon league every year with baby pokemon and more experienced opponents go easy on them as tradition.

They were all kids once, and crushing a kids dreams is cruel enough to make some people pass up the chance at a title for a year

The beginning of the pokemon league is a gamble, those who end up against kids are basically doomed from the start

This is why children don't seem to struggle at all until after the first round, because after that point no one cares anymore