DBD will die unless...
1) Remove SBMM and add in a competitive/casual mode. Disable SWF and super strong perks in competitive like COH, dead hard, Noed, etc. You might say this will split the playerbase, but it is better than losing all your players, and you probably would have more in the long-run on each side regardless from doing this even if it's cut in half temporarily.
2) Get creative with new killers, no more boring frankenstein monster design/powers where you just copy + paste 2 weaker versions of old killers together (looking at u sadako). Need a killer who can mind control survivors, summon monsters, etc. Too many killers just feel the same as others, and it is boring.
3) Perk point system to balance perks, increase slots to 8 for both sides and make each perk cost between 1-4 points based on strength. This is obvious considering how unbalanced perks in DBD currently are.