Your point is well taken.
However, that doesn't mean unethical practice should be tolerated even if they are "you know a business, not a charity."
The casino should choose slots with lower RTPs and not offer the ones with higher RTPs that they cannot afford. The provider should not create new versions of the slots with lower RTPs unless they give them a new name (like Book of the Dead Crap Version). Obviously the RTP is an extremely important part of the game, not just the colors, sounds, features.
If the casino cannot behave ethically and make a profit, then the solution is to close the casino, not fleece the players.
I proposed a pop up (like the ones for time spend and money lost) that would say "this game operates at a lower RTP setting of xx.xx%. That means your money will be lost a lot faster than the xx.xx% version."