If that's 100% the genesis according to Gnosticism, its hilarious how it failed to mentions the fruit of life that God didn't want Adam and Eve to eat after they consumed the fruit of knowledge.
Born and raised in a Christian home and still a believer, though I've fallen off church a bit. I was initially interested in the pilot for HH based on the concept. It was novel enough that I remember thinking that it could be a really interesting story if executed well. That, in the end, is what offends me most about the show: not that it bastardizes the stories and figures of the Bible for its own mythos, but that it does it so badly.
HH and HB have more things in common with goodbye volcano high than any masterwork you just mentioned: horrible storytelling, salvageable character designs.
Helluva boss in particular begs for someone to give it the Snoot game's treatment.
With Helluva it was the concept of demonic hitmen, but we saw how that turned out.
I want to say the demon hitmen concept is a good idea that requires a good amount of explainations to set up properly and questions that need at least a basic answer:
How do they do it was the single question that viv answered, and I bet it was done solely as a way to introduce her equivalent to Dave Filoni's Ahsoka (who too gradually turned to Mary Sue territory)
WHY they do it was nonsensically answered with "Money", but really isn't as most customers had just arrived in hell AND hell's currency is not well explained either and as a whole it caused more plot holes than anything.
Why wasn't it done done before (or IF it was done before) also was nonsensically answered, I think, since I am not sure due to not watching the season 2 and any explaination done at this point being a "too little too late" kind of response.
If there are consequences for doing it is something like "what stops imps from just escape to human world and live there happy forever?", which is not as far fetched as a question as you think and can lead to interesting ruling; for example: the cool solution would be having demons on a time limit when on the surface because they get sick if they stay too long, while the less interesting solution is just blaming divine rules or some other shit.
It's all homeworks that flesh out the world and create intrigue, all stuff that can take as little as 1-2 days of research and thinkering to write down, but Viv clearly hates homework and thinks there's no need to flesh out the world as she can just artificially make her own brand of emotionally driven intrigueslop.
The Hazbin Hotel interpretation of Hell is actually is contradictory. First it's portrayed as a brutal dog eat dog place where everyone kills, mutilates and abuse each other free of consequence (which makes the decision of reproducing there very questionable) then as a mystical version of your typical shithole liberal town's areas near campus grounds. Neither feel like a place of eternal suffering for the denizens beyond the usual liberal shithole town stuff. It feels like Vic's ego won't allow her to admit the main thing in her mind are gay twinks and the setting is just a cosmetic.
Under the hands of any other writer, making hell look like a slightly less shitty californian metropolis would have been the greatest piece of satirical commentary immaginable.
The closest I ever had to visit a big city has been walking trough Padua, I hate that place and los angeles is 14 times bigger and 100 times worse.