A lot of that is because the gods are usually part of some sort of pantheon or otherwise juxtaposed with other deities in some fashion. They have followers and creeds and lore and all these other elements that slot into the larger world. If you scoop them out, aside from just changing their name/look, you have to replace all of that in theory.
I find this surprising. I can barely get my players to learn the rules properly. I struggle to imagine people making lore accurate characters. One, because it’s a lot to learn. Two, because it’s specific and kind of dumb. We just use dnd canon at will to supplement but otherwise make everything up as desired.
In higher level campaigns, you can literally go to other planes and interact with the beings there. The deities in D&D are literal physical beings that you could just go and interact with (although depending on the deity and the context they might not take kindly to being bothered). A lot of prewritten modules specifically are about stuff with various deities; even Baldur's Gate 3, arguably the most played prewritten module in some time (it was popular enough to go mainstream and win GotY) heavily features lore from deities and in a few places in the story you (or another character) can directly have short conversations with some of the deities.
I don't see why it's "kind of dumb" if people enjoy playing that way. Tabletop RPGs have always had a wide spectrum of playstyles where some people follow the rules rigorously and some people ignore them entirely, and being consistent with lore is just another dimension on that. Every successful group will settle into a pattern that's comfortable for them.
The lore itself is kind of dumb. That’s ok. Most TTRPG stories will be pretty dumb. They can still be awesome. Imo plying your own dumb story is a lot better than someone else’s dumb story.
I would say it’s not ideal for different players to have different levels of knowledge about the world for non game reasons though. It’s better when most of it is freshly discovered.
In a current PF2E game, my Cleric has a deity and I do RP him to stay in Ragathiel's favor. It's explicitly called out and I don't think it's dumb at all...
Sure. But is Ragathiel any better than Bjorn’er, the god of rapturous dance that I just made up? Imo, no. If someone wants to choose a predefined god, sure. If someone wants to make one up? Also sure.
The only thing I’d be fairly vocal about is that until some lore has reason to enter the narrative, it isn’t canon. E.g. the space faring races that appear in both dnd and pathfinder
I mean, objectively yes I do think Ragathiel is better than Bjorn’er because there is actual lore, thought, and consistency there. [0]
Look by all means, if you want to bring your own deity or $WHATEVER to a table I don't think most reasonable DMs and players would even bat an eye but you'll absolutely be expected to put some degree of effort into this beyond just showing up unprepared and cooking shit up on the fly.
I would argue it’s even better role play if players don’t know things though. If you meet some followers of Bane, a player who knows the lore will probably deem them to be a bad guy. If they have no idea, they will roll knowledge to see if their character would know. The DM providing information based on character knowledge checks is generally a great source of fun.
The DM saying “yeah I know you know Bane is a bad guy but I made your roll for it and you failed so you need to pretend you don’t know that” is never very good even if the players try to obey the spirit of things.
Indeed, some folks do re-role until fate favors their egos... lol =3
In a way, the more modern video game mechanics based on traditional starter-map games must also choose between a chaotic open-world, or a structured linear mission story (often degrading into a rail-game like snakes/chutes-and-ladders.)
Certainly, many of the iconic characters were a mix of several genres:
My primary gaming group everyone goes out of their way to learn the rules and make lore accurate characters, or build onto the lore. Regardless of which system, setting or game we are playing. We do a lot of homebrew though.
Different strokes for different folks. Many people actively enjoy having a mass of written lore to consume, and prefer having a well-defined setting to act as a foundation to their stories. It's a safety net of sorts.
Back in the day we’d play the same characters for a year or so. Some background lore is nice to have in this case. It makes everything more interesting.