Adventurer with Fairgrounds has to be fairly heavily driven by the need to collect 15 unique cards. Besides, even as a terminal silver, Adventurer isn't that bad if you need to hit 6. A overpriced terminal silver/gold can still be better to get in deck than a lot of terminal cards (e.g. Secret chamber, Moat, Oracle with too strong of reactions out, mandatory trashers like Remake or Rats when you have a thin deck, Coppersmith without much copper in deck, Hag when you opened Witch, Duke, Potion & some Potion cards, Contraband when you really need to be buying Fairgrounds or some pricey unique) at some point in the game after you have a gold, but don't want to buy a Fairgrounds and the other options are worse than Adventurer, then yeah getting one makes sense even though it is overpriced and a terminal.
My complete WAG for university is potion diving. If you trash out your coppers, the adventurer is sure to leave a potion in hand so you can buy Uni or some other synergy card. E.g. I could see Uni/Adventurer/Vineyards/trashing/no other draw working something like - buy enough Unis to gain enough actions. Buy Adventurers to assure buying a Vineyard each turn and to avoid a potential 3-pile until your Vineyards are worth more than provinces. Another shot might be some sort of copper trashing environment with junking attacks - dive for the potion, use the Unis to build economy with actions. Both seem to be a stretch, but maybe it works.