The I/O threading was initially implemented by myself, when I was still working on the core before rejoining, and is also available in Redis. So this is actually another case of the benefits ValKey got for being able to clone Redis, receiving money from the hyper-scalers that just want to maximize their revenues...
They made certain improvements later, but Redis 8 (see the release notes in my blog post if you are curious) improved this stuff a lot, too.
Also, Redis 8 contains a new data structure, Vector Sets, that allows to do many useful things, together with more probabilistic data structures, single hash fields expires, and many other stuff. It is not factually correct that ValKey has any features edge over Redis I believe. We will see in the next year which project takes the best development path: this is what really matters.
They made certain improvements later, but Redis 8 (see the release notes in my blog post if you are curious) improved this stuff a lot, too.
Also, Redis 8 contains a new data structure, Vector Sets, that allows to do many useful things, together with more probabilistic data structures, single hash fields expires, and many other stuff. It is not factually correct that ValKey has any features edge over Redis I believe. We will see in the next year which project takes the best development path: this is what really matters.