In Stack Overflow generally the correct answer is often the second most upvoted answer. This is because the first answer was right but things change.
I'm already seeing here that I would like to unvote old out of date answers but can't because the answer "hasn't changed". This is true but the world did.
The easy answer would be to let people unvote. I'm sure it was prohibitied for a reason but possibly that reason doesn't really apply to a more focused community where abuse is less likely?
The more general fix might be to vote an answer as being "outdated" just as we vote to close a question.
It would be cool if the right answer was the top one.