This is all correct if you only watched the first seasons only. Answering critically.

If you go further, you'll see a bigger picture. If you are on season 6, and think "now I understand" - lol - don't hurry with the conclusionы.

Supernatural is an original explanation of the Bible and the Apocalypse. If you watch more seasons and you'll see the way they explain Christianity, and this interpretation will never abandon you, as it's too convincing and exciting.

Dean and Sam start as just guys traveling in the US and shooting ghosts and ghouls but after several more seasons, you'll ask yourself "are they actually humans?" Can they even die?

Definitely, they aren't just simple guys. Even their birth was planned - not by their parents. Or another fact - Sam's life after his leaving his dad and brother was fully faked by demons. Slight spoilers, just to give a broader perspective.

Those stereotypes will fall apart if you continue watching - cynical Dean driving an old car, listening to old rock, wearing an old leather jacket, behaving like a macho, and Sam, a university guy, eating healthy food, reading smart books, with liberal values - these will fall apart. Sam is sympathetic, empathetic, kind, but actually he is the one who will be carried away towards evil, while simple Dean will be saving him from that, learning on the way compassion, empathy, forgiveness.

Easy show to watch - that's true, it's like a comic book. But within its genre, it has deep philosophy - while so many TV shows focus on money, sex, success and childlike saving the world with pure black and white on the scales, Supernatural raises the question many of us know from Crime and Punishment - does the end justify the means? Supernatural is literally fantasy Crime and Punishment.

Being morally tortured from inside, feeling painful guilt for mistakes, and being murderers for the common good is a signature of Supernatural.

They have silly episodes, they have weak places, but overall, it's an epic show. Marvel series, they were selling as stand-alone movies, are much, much weaker, with a very bad plot, with just separated parts that were really fun (like, Guardians of the Galaxy and some others).

I think people will keep watching Supernatural, unlike many other shows. It's unique, it's deep, and it has its style. Guys invested so much energy and talent in it - it happens so rarely.