If somebody new read the old post I just linked to and resteemed it; and some of his followers did the same, I'd be delighted. People can still reply to it and share it. They can follow me. I can reply to their reply, and they can upvote my response; there's a heap of ways older posts can benefit an author.
I did a post 'Sudoku without Numbers'. Its 2 years old and its on the first page of the google search results. That's fantastic, and plenty of reason to pour effort into a post.
That may not translate as quality, which is fairly subjective; but its justification to give it a red-hot :)