I'm not against learning or understanding the nature of the issue so that I'm in position to form a correct solution. But I find it kinda funny that topics are locked with "duplicate", and the question linked has for example an accepted answer written in PHP5. I believe that SO should invent a way that such cases can be updated without the current "hacks". Now, even if somebody puts the effort to write an up-to-date answer, it will be at the end of answers and it will take a lot of time, if ever, to reach a higher position. Also the "accepted" answer will always be the old one.

Another issue is that in some cases, the accepted answer becomes a wiki. Edit upon edit by users with required reputation adding new up-to-date info. In the end the answer is nothing close to what the original answer was, but it keeps the originally acquired score. So it can reach to a case that you see a +100 upvoted answer, which in fact has only been proof-read by 2-3 people, the ones that are needed to accept the edited answer.