I'm currently fighting in DW with both my accounts and deep inside the top 10, and can tell you the new streak format hasn't incentivized us at all. Nor has it made match ups more competitive. Without stages in the heroic quests, there's not much to really fight for.
Eventually, as the top 50 individual players in the top 3 guilds reach 2 billion stats from all the individual alliance boosts and the gap in stats get wider, the rest of the players from top 10 guilds will become very indifferent to the game and quit, as they will know they can't keep pace with the stat inflation. Simple human nature: the more something depreciates, like one's KA account, the easier it is to give it up.