The thesis would consist that, although the probability of winning classical lotteries is near zero (typically between 0.0000007% in the case of Euromillions and 0.000003% in the case of national lotteries), people is willing to pay an excessive overprice because they are buying the right to dream about the possibility of winning.
You cannot argue with people who prefer to chase their dreams and they are willing to spend money on it even if the chance is very slim because they see winners and their dream is the be the next bettor in line to win, people bet on the lottery because it is their shot to get to their dream because their jobs and the present situation will not let them gets closer to their dream, only by betting in a lottery they have a chance to do so and betting in a lottery is addictive, when you are chasing your dream and you have a way to do it even if it's impossible it's addictive to follow that method.