What happened that made casinos change the payoffs on their games? What made them tighten their slots? Lower the paytables on video poker? Change the rules and the payoffs at blackjack?

Today, it is very common to find 6:5 blackjack where 3:2 blackjack used to be played. And today there are casinos that offer 7/5 Bonus video poker instead of the higher paying 8/5 video poker? Why?

I ask why because the casinos still made money with 3:2 blackjack and the casinos still made money with 8/5 Bonus video poker. Is it only greed? Is it because they overbuilt and now have too much debt to service? Is it because they have added so many shows and pools and spas and luxury rooms that they need more profits from the casino to subsidize the cost of the hotel and resort amenities?