It’s wrong and misleading, and the "it’s Austria to save you a click” makes it worse, since you are inviting readers to digest this knowledge using only your misleading title and that sentence.
It’s rather amusing you can’t be bothered to fix your title when you know it is clearly wrong and you are willing to instead spend time defending your title in the comments.
There is enough poor content and misleading journalism on Reddit and elsewhere, I’m not sure why you want it here.
Now, since Austria is the happiest country in the EU it is quite possible also the happiest country in Europe. But we don’t have any source for that, so why defend it?
I'm not defending the title. I hate clickbait as much as anyone, which is why I put Austria as a comment.
If I had changed the headline someone else would have objected to that. I use the one the paper sets. Always have, always will.
But if you feel so strongly about it, make a post with a headline that you agree with. Nothing stopping you.
Or just accept that papers have bad headlines sometimes and move on.