Grian is less of a "oh woe, is me, I live so long I'll watch everyone around me die" person and moreso a "oh, a weird artifact, let me take a Look. *Purple magic stuff* Yeah, I've seen this before." Person
He's basically Skips from Regular Show
As a Watcher, he's seen it all, and therefore helps the other Hermits with ancient or dangerous artifacts and such that they can't identify themselves
(And I mean that last part. Do you know how many Hermits are magical or deities in their own right? If they don't know what it is, then it's some serious stuff.)
After this many years at that game, he's learned to identify pretty well when the "big scary magical item" he's being asked to identify is actually just Some Other Hermit's Nonsense. Oh, that? That's not a cursed artifact - well it is cursed alright, but it's quite a new cursed item, actually. It's just Doc's backwards torch. Yeah I don't know how a torch can be backwards either, but that one sure is, it's some kind of game breaking trickery as usual. That one over there is just one of Cleo's heads. That's the magic item Ren uses to change between all his personas, and that - hang on, that's just Joe! You can't submit an entire Joe Hills as a magical item! Go away and let me get back to work!