True, Dedicated servers are the answer. The same with stricter matching systems, games ending without a winner or victor because someone left less than a minute before the game started(like overwatch) or even larger maps because most D2 maps are totally 2v2 maps and definitely not 6v6. However, Bungie can't exactly just change the way their entire matching system works toward the end of their games life. That would be risky and costly. Hopefully, they put them in destiny 3 but you have to remember that dedicated servers cost more and Activision isn't really a fan of that word.