Well, I suppose there is "trial and error" grind which most find acceptable - although I don't really like it; as a player I want "all the pieces to solve the puzzle" available at the start and don't like "failing" because information was withheld from me. [1]
Then there is grind "grind", where you do the same (relatively simple) mundane thing over and over and over again - this few find acceptable because it's hella bothering.
[1] The classic examples would be NES games where you practically have zero time to react to the one-shot kills and have to pretty much memorize the level to get past them.
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I suppose there is a reason Blizzard has removed ALL "prep" for raids - attunement, consumables, resist gear ... etc.
Most likely it's because a huge number of players didn't like it.