That's too harsh. It depends on the operation and the probability of success. If the operation is non-critical and succeeds 99.99% of the time, it makes perfect

That's too harsh. It depends on the operation and the probability of success. If the operation is non-critical and succeeds 99.99% of the time, it makes perfect sense to show the user an "optimistic" result. This is the same principle that multiplayer games use. When a game character is moved in a particular direction, the client shows "optimistic" movement before the server confirms the movement. This is the difference between a playable and unplayable game in many cases.