In the Mysteries of Summer questline, Pearl Abyss added a puzzle that is solveable only with luck and enough silver to pay for repeated tries. Knowing the solution doesn't help, as even that is RNG. That's exactly right. The solution leads to a lootbox where you may NOT obtain the completion target, despite the fact that the whole event is a race.

We, the players, wasted millions upon millions, some have wasted BILLIONS to be stuck at this point in the race, inside a pitfall of a quest that requires you to buy a chance to win a lootbox that has a chance to let you out of it so you can continue with the race.

This is unnaceptable. Utterly ridiculous. Players have wasted TIME and MONEY to get the key, and despite knowing the solution, the vast MAJORITY cannot get it.