Yes, that's how the structure of journalistic writing used to be. Necessary information and main takeaway followed by additional context.

Now you get a clickbait headline followed by a paragraph and a half getting to the main point, but just before it does, the paywall, subscription box, or whatever appears. Because of that, occasionally people will provide the main idea/point (tl;dr), and people then decide whether they'd like to read it or not.

Your concern, I think, which I happen to agree with, is that people less and less bother to then read the article to gain better understanding or context. But it's worth realizing that in a time when people read a lot more, headlines actually served roughly the same purpose as a tl;dr does.

The headlines need to be more truthful. It's not the stupid people that read a headline, and then are disappointed in the actual story that doesn't match what the headline said.

If the head line reads "Aliens land in America!" And then it turned out to be about immigrants from Europe I'd be pretty upset even though the headline is technically true, everyone reading it is going to assume a totally different thing.