Local caches and local node caches are both very useful. (That's why Redis 6 introduces this https://redis.io/topics/client-side-caching), but anyway from what I saw in the past, the major speedup of using Redis in such a context is that you want to use a shared very fast view that is global in nature. A simple to understand, but good example, is the leaderboard problem in multiplayer games that have million of users (Facebook games and such). Even if you have a local cache, and even if you have an additional store where you record the high score of each user, you need a global and very fast to update view of all the sorted scores, to tell the user its rank, users nearby, the rank of their friends. There are a number of problems like that that require to use different data structures and a global view. The problem is that using Redis with the Memcached mindset, will always severely limit the potential benefits.