I don't think first person works where the canvass is broader and the story has several facets and, perhaps, a number of MCs.. I can't imagine Joe Abercrombie writing books like "The Blade Itself" in the first person, or G R R M. So, really, it's a question of "horses for courses." If your story is of the kind which lends itself to first person narrative, go for it. If not, stick with third.
Actually, I can imagine
The First Law trilogy in multi first. The author did such a good job of making the narrative voice different for each pov character, he could have pulled it off, I think. It worked just fine the way it was, though.
I remember reading in his blog (or maybe it was an interview somewhere) that in the version of
The Blade Itself Abercrombie originally subbed had Dogman's pov in first (the others in limited third still). His editor felt that keeping it this way would mislead the readers into thinking Dogman was the main protagonist, more important than the others, so he changed it to limited third during revisions, trying to keep the voice and style as close to first as possible.
I don't feel that George RR Martin's novels would work in first, however. There are so darned many pov characters, and he spends a lot more time with some than others. And his style of limited third is a bit more distant. There's some character voice in the narratives, but it's more muted.
I love first-person narratives because they make me ride around inside a character and learn what's going on with them. It makes me feel very invested in that person and makes for a lot of empathy. But I also enjoy limited third narratives when they do something similar. Omniscient can be fun too, if the narrator themselves has a great voice and adds just the right blend of insight and mystery to things.
Rowling hit the right notes there for me, as did Adams and Pratchett. One reason I've had trouble getting really pulled into Scott Lynch's books, though, is because the omniscient he uses feels a bit like it comes between me and the characters' emotions. It's frustrating, because I love his blog, and they're the kinds of fantasy novels I
should like in terms of world building and story type.