They get paid because the people who can't play chess professionally watch it as a mental escape from their drudgery jobs because it reminds them of their youth when they could still dream about becoming a great chess player, and then you can use marketing displayed during the chess tournament to trick them into preferring to spend the money they make from the drudgery on the adveritser's product.

Now upgrade AI to do every job better than humans so that there are no drudgery jobs. What money are they going to spend?

Not too long ago, people would come and visit the first family in the village who had installed running water, because it was a new and exciting thing to see. And yet people don't wake up every day excited to see water coming from their kitchen tap.