It definitely is. I do hard mostly for the fish and the runes, but the scales and energy are also welcome.
What I don’t understand is why do people have to choose their next goal. I mean, unless people calculate fish and gold per energy and think: “Okay, I’ll gamble that the Duties aren’t broken and if I don’t get a 5\10key chest within X hours, I won’t be able to spin the grind wheel” - there is no reason not to pick the hard chest.
In fact, if we could just accumulate the keys and select the chest at any point so long as you have the keys - it could be a good way to take a smaller chest if we really need the resources asap.
But since this isn’t the case, and the Duty RNG goes from nonsense to broken nonsense, and you could get a Hard Chest in less than a day, or maybe even two days won’t be enough - I’d just take the best I can get.