Regarding slots, it was my understanding that it is the most profitable thing for casinos, but your reading here is the opposite. I know you are an expert on the subject and you have your thread on it. Are you sure that those percentages refer to the revenue that the casino gets? If so, I imagine that slots can still be more profitable for the casino than other games because they have lower costs, for example they don't need a dealer, and they can be played faster (although they return less in prizes, the higher the betting speed, the more people can lose by compound interest).
Yes, it basically needs electricity and space to operate, unlike table games which casinos must hire a lot of people.
As you can see, the biggest revenue comes from slots due to its faster game -> 4x more wager than table games -> higher revenue even though the casino's win% is significantly smaller.
In the end, slots is still considered most profitable because of its high wager/turnover plus lower cost, not because of its house edge/casino's win%.