I'm not at all sure what you mean with "a perverse pit of debauchery". Apocalyptic Mad Max/Dark Angel, or what a school teacher from 1850 would say about the sexual habits of millennials–or pretty much anyone from the 21st century?
But I hope my answer will be applicable regardless!
Even if society gets really bad, chances are your characters won't experience it first hand, rather second hand:
Gang-rape, murder spree, the headline read. He swiped to the next news item. Drug addicted criminals, he thought. Whores and alcoholics... out to paaarty. He could imagine them wail the word in a drunken stupor. Probably got exactly what they deserved. Idiots!
You can get a long way with a bitter character commenting on the state of things. Not just their comments but the character itself giving a picture of what place we're in.
If you repeat it a few times. It will sink in. Especially if the characters just shrug it off and move on with their lives.
You could even spread it really thick:
He swiped past the "rape and murder" section of the news feed. He liked to think of it like that. Local news. He skipped the "drug and gang-related deaths" as well. Misery and idiocy! There had been a lot of existential angst and meaningless death for a while now. He needed some lighter entertainment. The sports section. At least when someone got killed or maimed in sports it was on purpose.
Other examples from the character's everyday life could be:
- You die of pneumonia because of course, we didn't manage to prevent resistant bacteria
- Every month you pay rent, and for protection from the local street gang
- Sounds at night, of drunken orgies turning into fights, turning into police sirens, turning into people crying in despair, etc
- Or a paraphrased favorite from Dark Angel (because, of course, the original quote wasn't googleable...), "You got a job? And you get to keep your clothes on? Wow! Congratulations."
You can be secretive about it and sneak a few hints in. Or have explicit characters pushing the point with commentary or even showing by being assholes themselves—the kind of voters needed for your society...
These could be small side roles, perhaps a taxi driver talking about the news, or it could be one of your POV characters doing a running commentary of society's downfall throughout the novel, while fighting crime, or demons, or corporate lawyers.
On a side note though.
You say you want everyone to read this. You can't make everyone happy. Ask any politician... Also, bookstores can only place your book on one shelf. It's in your best interest to help them decide which.
You should decide about a genre and a target audience for your book.
Once you have that, you can read books from that genre and for that target audience and figure out what you can and cannot include.
If it's a children's book, then it will be written from that perspective, protective parents hiding a lot ("Life is Beautiful" comes to mind) and the child understanding only parts of it.
If, on the other hand, the audience is grown-ups, you can be more direct (along the lines above—you still don't have to make apocalypse porn out of it...)
Teens have to get permission from their parents (in most cases) before they can pick up your book, so you need to tone down some things. Reading the genre should tell you what.