This is because the paper already had your money. Nowadays, news sites don't make money until you click each story. A sad situation for readers.
I have read the article. I can make an attempt at an old-style headline. Something like, "International cooperation halted the depletion of the ozone layer 1989-2019." Less enticing, eh? Now you know whether you really care for the details.
Which brings me to another problem with the article: it could be a third as long. This was a general problem even pre-internet, moreso in magazines than newspapers, which William Zinnser pointed out in his book On Writing Well. The first few paragraphs can often be excised, with nothing lost. It's as if the writer is warming up to writing the article, out loud. First there is a lot of philosophy. Then there is what could pass as an encyclopedia entry for Ozone Layer. Then a human-interest story of the discovery of the hole. This has its place (like in an encyclopedia) but you need to bear your readers in mind, and you are doing them a favor if you omit information that most of your readers already know. No need to bring newborn babies up to speed with each article.
The headline isn't even accurate, because we have not "fixed" it. The damage stopped at the beginning of this century, but the article itself says that the layer won't completely recover until the end of this century.