Back when Aurumoth was just a concept and some numbers, I was a bit naively optimistic. I wasn't sure how it could be anything other than risky with a Bug/Psychic typing. I thought No Guard would be the most viable and popular ability. I voted for the absurd movepool it ended up with. It wasn't until I dove into the new post-CAP4 playtest meta and started battling against it that I realized what Aurumoth was.
I remember there was sort of a new concept floating around during the movepool stage, that Aurumoth should have no hard counter but plenty of situational checks. That is much closer to what Aurumoth ended up being than the original concept, and I believe this divergence is what harmed it the most. Facing Aurumoth forces me to play extra safe until it is eliminated, and that alone mitigates risk somewhat for the Aurumoth user throughout much of the battle whether they realize it or not. The sheer number of possible sets makes hard prediction (and thus, hard counter) all but impossible. When used smartly, Aurumoth has consistently guaranteed at least one KO against my team, and I suspect it does the same against many other teams/battlers. I've rarely found it to be devastating but I see very little "risky business" in using it the way most players do.
However, I think Aurumoth being so versatile allows for a lot of creative set and team building, and several Aurumoth users have gotten a "that's pretty clever!" out of me. I don't see Aurumoth as a complete failure competitively and I don't think its boosting moves are the worst part of its movepool. I also don't find it to be anywhere near as annoying as Krillowhatthefuckthisthingneverdies, so I guess that's something.
EDIT: There's something else I forgot to mention. I think the rule about the number of total moves and very good moves allowed was unhelpful. Rather than a large, suitable movepool that fit the flavor and didn't necessarily have all that many amazing options, Aurumoth's movepool ended up getting stuffed with nothing but the very best. I did attempt to create a movepool for it but found the limits to be restrictive. I know I said the boosting moves weren't the worst part, but consider this: Swords dance, agility, calm mind, nasty plot, and cosmic power are all VGMs and none of them are as good as what Aurumoth ended up with. It would have required much more thought and consideration to use Aurumoth effectively if it had gotten all of those instead of just the big three. These kinds of changes from top to bottom would have been beneficial. Submission, Reversal, and Superpower instead of CC, Flame Charge instead of Overheat, Aqua Tail and Water Pulse instead of Surf, Grass Knot, Charge Beam, Ancientpower, Signal Beam, and so on.