Maybe a stinky opinion of mine, but I think the exp payout for casino is probably one of the worst ones out of all the plaza activities out there.
Recieving 2.5k exp every 15 mins feels really damn slow compared to the Theatre, where you’d be busy for hours watching videos and getting 5k for it.
I cannot sit longer on a slot machine due to the backend sometimes dropping out every 5 or so minutes and honestly, it gets really boring really fast. Other option would be to alt-tab every minute into the game and have the exp slowly build up.
I get the idea that those milestones are suppose to be a long-term thing, but no other plaza activity feels this grindy compared Theatre or Trivia