Not knowing what to do? - Fine. Not gonna debate that.
But spending 10+ minutes flapping around and not even being sure I'm making progress? - Yeah, that's gonna turn off a lot of people.
The point is that it feels like the player has very little agency in what's going on. Might as well be a slot machine where I can just pull a lever and hope I get the "damage boss" reward. Have you had anyone play-test this at all?
Player skill should trump randomness otherwise it just gets frustrating and people give up, like I did. In the end there are plenty of other games where people can go spend their time instead of yours, so don't give them a reason to think in those terms.