Ironically, I see the Realms as more inherently dystopian. Yes, the Realms have these big, huge nominally Good versus Evil showy fights, but they are nothing but spectacle orchestrated by the deities in order to increase their own power by keeping souls captive. In contrast, GH seems like a better place to live in, yes the world is crumbling, and nothing is so big scale, but your choices are yours, you are not a pawn in a bigger game. Just you, and your friends fighting again the world.
This is a totally valid interpretation of the Realms, but it's worth noting that the Realms has, AFAIK, never, in any book, whether it be setting, novel, or whatever, really been written that way, and Ed Greenwood clearly doesn't see it that way, and thus tonally, that doesn't come across unless the DM is pretty lore-literate and decides to make it part of the setting.
Ironically, Ed Greenwood's own sort of "day to day life in the FR" book, despite seeming not to believe in the Wall of the Faithless (and indeed not mentioning Kelemvor at all - he's not even listed as a god or mentioned in any way!), still manages to project an extremely dystopian/oppressive-seeming vision of worship in the FR, which is basically that if you don't worship the gods, you're going to be punished, severely, and also no-one will like you or help you. It further confuses matters by seeming to suggest that opposing or hurting the goals of any god means you're stuffed, including evil ones (which is deeply confusing because a huge amount number of FR adventures and novels, including ones by Greenwood, are specifically about doing that).
I think what this shows is that the FR is a pretty clumsily-developed setting, where there's a pretty serious discontinuity between the desired tone of the setting - fairly upbeat high fantasy - and the specifics of it, which are pretty much YA-novel level dystopian if not ignored. I imagine Greenwood could explain it more cogently in person, but even when given an entire book to make the FR make more sense, he only manages to make it weirder and more questionable. Also the man should never be allowed to name food, drink, or really any kind of object or festival or practice. People, places, okay, it's not for everyone but it works, but other stuff... hooo boy.
