Oh, there is absolutely a purpose in an immensely powerful cosmic evil. I can see that easily. What gets me about the "not conflating archfiends and gods" is that, well, that was commonly the case. Beings like Belial and Pazuzu and others were gods of other cultures, that the records we have now call "demons" because they were the gods of those people's enemies. The monster Python that Apollo slays to free Delphi is actually a protector God of the Minoan people, to give another example.
So, with synectrism and other such factors, it actually makes a lot of sense. Because the majority of the beings whose names we associate with demons and devils were gods, just other people's gods. The idea that Archfiends are just evil gods is rooted in this same concept.
Yes,
but. And that
but is that these entities not only actually and provably exist in D&Dland, but have defined powers and abilities. And again, we
don't have stats for gods of any alignment in 5e (the actual god, not just an avatar), but we
do have stats for arch-things. So what's the difference between a god and an arch-thing? I don't know.
To move away from Bane and Asmodeus for a moment, gnolls probably consider (inasmuch as they can consider anything) Yeenoghu to be a god--but he's not. He's a demon lord. So back to the main question: what
is a god? If it's just a title given to something that's worshiped (or venerated, sacrificed to, whatever), then Yeenoghu--and Asmodeus, and Orcus, and anything else that has followers are gods. If there's something
else that differentiates them? Then again, I don't know.
So, again, I think there are more benefits to mortal worshipers than just dealing with the Blood War. Especially since these tempations and deals are still happening, even with the Blood War going on.
Yes, there are benefits to having mortal worshipers. But unlike gods, fiends don't have to rely on them. If their supply of mortal worshipers was completely cut off, they'd be inconvenienced, but they wouldn't
die.
And quite frankly, fiends are
never going to get as many worshipers as any of the regular gods get.
Sure, but I interpretted your original assertion as without the Blood War Demons would just ignore the Prime and focus on infighting in the Abyss. That isn't the case.
They wouldn't ignore it entirely, but I doubt it would be a main target. Unless a handy portal appeared.
to an extent. But that doesn't mean that all of us like the redundancies.
No, of course not. But there's a huge difference between "I don't like these redundancies" and "these redundancies
should not exist at all." And you've been leaning towards the latter.
And I say, why not? Sure, they can be annoying, because the average setting doesn't really have room for or need that many types of low Hit Die humanoids, especially if each of them has a culture of their own. But they can also be useful,
especially if each of those low Hit Die humanoids has a culture of their own. Same for gods and arch-things. Hell has interesting conflicts--not all of which are actually combative--because of the rivalries of Bane and Asmodeus.
Any of these issues could spill out to the Prime and make for interesting drama. Imagine if you had an elf cleric get looked down upon by fey because he follows Corellon and not the Seelie Court.