I think my issue is that the game starts off going to 100 real quick on the epic scale, and I don't see the game being able to convincingly bring the pacing down to something more normal/mild without it feeling awkward and forced. WotR in comparison probably starts off even higher on the epic scale, but its companion cast is still rather largely grounded (and effectively dulling a lot of the edge through their party interactions and constant interjections). Plus the overall framing and your party actually participating in almost every conversation makes it extremely clear that you're in a turbulent region of the world widely known to be affected by extraordinary circumstances - but it also doesn't mean everything has to be extraordinary.
But BG3's companions and the overall plot just pushes the epic scale as high as it can, and it's also a big contributing factor to the worries that custom MCs are going to get the shaft again. I mean, you've got a Githyanki that isn't normally seen in the setting, a mysterious cleric of an evil goddess with a crazy maguffin artifact, a wizard that people theorize is a reincarnation of something close to the freaking goddess of the weave and source of all magic, a vampire spawn, and a warlock beholden to a cambion. Like they're all really damaged in terms of backstory and personality, and it shows with how little actual party banter exists between them, or how their backstories don't lend themselves to any semblance of potential future character development that doesn't involve five layers of mystery being peeled away or murderhoboing something. Let alone themselves actually interacting with the setting that they're supposed to be from without something exploding. Kind of telling that none of them talk about their family or ever having any friends before any of this began - meanwhile all of WotR's companions do, even if they're only slightly lower on the epic scale in a direct comparison (and some are even higher, such as the succubus Arueshalae, but she gets utilized in a way that really adds to the characterization of the party as a whole, not to mention offering a unique perspective into the lore of the setting rather than trying to become so epic that their existence comes off as trying to retcon something).
Literally any of them could be a main character in their own separate games, and maybe that's the point with the existence of the eventual Origin system. But really, how the hell do you balance that kind of party from a narrative standpoint against everything else that's happening? That kind of competing focus not just drowns out whatever perceived role a custom MC should have, it also overpowers the actual setting itself.
I've come to realize that throughout my time playing BG3, not once did I really feel like I was really playing a game in the Forgotten Realms setting (and I wouldn't have known it was a Forgotten Realms game if the game didn't take every opportunity to tell us it was, rather than showing us in a sense), because a lot of the background details feel like they've been completely overpowered by the extraordinary events happening to your party and the surrounding areas. With the way things are, it almost feels as if we as players got dropped into something in media res, except it's the beginning of the story rather than something that was done on purpose.
