The sccache description was written before remote storage was added to ccache. Remote storage is a relatively new feature for ccache, and it didn't exist when sccache was created.

The ability to use the local and remote caches in tandem is the most important feature to me. sccache will use one or the other exclusively, so successive builds will have to pay the latency and bandwidth costs every time an artifact is built rather than just unpacking from the local cache. ccache stages remote artifacts locally by default, so it only pays the network costs once per artifact. In CI builds they are more or less the same, but the local build experience for ccache is much nicer imo.