Above the answer list, there's three tabs: active (descending by change), oldest (ascending by age), and votes, the last one being the default when you haven't changed the order.
In all of these sort modes, the accepted answer is first only if not by the same user as the question.
So your request is actually the default, and (AFAIK) has been from the beginning. Open a private browsing tab to get rid of your cookies and see for yourself.
