So it depends on who and what a game is for, whether these choices are good. AlsoFor example, many big games really aren‘t a single game. They are more several games merged into one, to appeal to the broadest possible audience and make enough money to recover the huge up-front costs for a professionally acted/mition-captured, voiced, scored and textured game.
So you‘ll have players who want to compete with other players, who only care about the battle mechanics. You have others who only want to experience an interactive story, and find the battles between them a chore, and again others who are mainly looking for a crafting game or a resource management-or or trade simulation-simulation.
In multiplayer, that‘s not really possible, so you match up players with similar rank/gear and adjust difficulty for the whole match.
However, these are all fairly "above the table" tricks. Every player gets the "secret double-damage last bullet" and can take advantage of it. Most peoples' intuitive understanding of how likely a "50% hit chance" really is is wrong, and they will be helped by telling them the percentages "translated" into their "language". What, as you say, about "secret" tricks?
Well, if a game was like chess, and you were told one set of rules, but really those were a lie, that would be cheating.
But none of the games in recent articles I've read on game developers' tricks to make you feel better were actually like that. Most were story-heavy games, or games that are famous for invoking a certain mood or feeling. And in that context, displaying 100% mathematically correct health bars makes the game much less exciting.
It's like a magic trick: Players go in expecting to be served an illusion, so I think it's fair to give it to them. It's also like a magic trick in that some people will still want to believe there is actual magic and will be disappointed when they find out about the trick.