Why is this movie considered good.

Yeah/Nah.

It's not a boring montage of murder. It's a gritty look at how the underworld operated at the time, and it completely showed the stark reality of how unglamorous the mafia was in all its horrible glory. Yes, most of the characters were about as interesting as cardboard, because criminal sociopaths are soulless human beings devoid of real emotion or personality, no more interesting or personable as a cold blooded pit bull.

And yes, Henry Hill learns nothing, because he's a weasel who only ratted everyone out of self preservation, not for moral reasons. He is not a hero, in other words.

To appreciate this film more, watch all the gangster crime dramas that came out after Pulp Fiction, starting with The Usual Suspects. They all glamorized gangsters as cool, charming funny hipsters with guns or antiheroes who you wanted to hang out with and the gangster life as a cool fantasy. This was the very last realistic gangster drama.

Wow, you're delusional.

The movie is actually about selling!

The selling to the audience the appeal of the criminal lifestyle 🙂.

It seems to be little more exciting and fun than working at Amazon 50 hours a week.

Excuse me, I'm going to do some coke and make some spaghetti sauce. (I have to do this every time this movie is mentioned)

Because the majority of people who’ve seen it considered it good.

Why does the OP assume that Henry Hills character should change? This is a movie based on a real person and that's how he was.

To give his some sort of redemption or come uppance at the end ( though he was captured) would be absurd.

Yeah, it's so easy to introduce drama when you have someone using a gun every ten minutes. Now making people laugh -- that's hard.

A couple of hours of northeastern urban psychopaths beating, torturing, and killing each other is splendid entertainment. Not only that, but for Scorsese and his stars, De Niro, Liotta, and Pesci, it was really stretching themselves outside their comfort zone. It's not as if Scorsese directed or those guys acted in this kind of thing often.