They pretty much spoiled the ending at the start

I wish they ditched the contemporary introduction.

Yeah, we know the two Swedes live

I never understand how adults seem to think films are like gift wrapped presents.

We don't know what's inside, we don't know how the movie ends. Once we do, the fun is over.

Next time I look at Picasso's Guernica painting, I'll say -- "seen it all already, nothing new here."

Not to mention, we saw the remains of the ship underwater, so everyone knew the it would sink at the end

It was a happy ending because we got to see Leo die!

The OP makes a good point.

I myself did not know of the Andrea Doria before George Costanza wanted to get a new apartment.

It's totally conceivable that today, 2021, theater-goers (lots of teenagers) would not know about the Titanic.

It's like the covers and posters for Planet of the Apes that show the Statue of Liberty.

That's not the twist that the film was building up to. What it was building up to was: Is Rose lying or is what she's saying credible? and what happened to the diamond? Neither of which were revealed until the final 5 minutes.

In most movies, the lead character typically always survives during tense scenes.