The rules there just don't encourage updating answers or re-asking things already asked. I've always said, StackOverflow is a great resource if your specific question is "How would I have done this programming thing back in 2010?"
Ironically, I predicted this already back in 2010 (or whenever the site started). I knew from the outset that disallowing duplicates forever was not future-proof, and that the voting mechanism will favor answers posted earlier, not answers that are more correct or up to date.
