The law in most countries supposedly, explicitly, would want to protect the general public from being exploited.
It presumes to accomplish this by banning games based on luck, aka chance, aka randomness. However, in actual fact, and if indeed the game is randomly and fairly played (e.g. a lottery, dice games, keno, roulette, bingo), each member of that general public stands an equal probability of winning! It's the perfect leveller, chance is. There is no possibilityy of 'exploitation'; all one needs to know is one's actual chances of winning, which would be a trivial matter. And then, if one would want to, one would plunge into the game with one's eyes wide open -- but, importantly, without risking to lose more than what's prescribed!
On the other hand, games based on skill (e.g. poker, chess, billiards) are expected to be won by the better player, and not by "anyone". Nothing democratic or egalitarian about it. The majority of the general public, in games of skill, is expected to be taken to the cleaners by the ablest minority. (Most humans will overestimate, in general, their skill at any game they choose to play.)
Why does the law allow skill and ban randomness ?