This thread is my first time hearing of it, it doesn't seem particularly established/mature (e.g. I can't find cloud services offering managed instances, whereas there are plenty of those for Redis)
Are you suggesting that there's no need for Redis to integrate persistent-storage support because every user should download some library and patch the Redis source themselves? And that would somehow be better?
I'm suggesting you haven't read enough before replying, just like I did on my first comment. See "Myrocks" as an example of what the first user meant with lmdb. Replace "mysql -> redis" and "rocksdb -> lmdb".