They appear to be answering different interpretations of your question.
As @Conan_Kudo says, you’ll need to have the core snap on the system to support snapd itself. That snap will likely get smaller in future though.
However, from the point of view of an application snap, base snaps can mean that the current core snap is effectively invisible: you can pick another snap to act as the root of the file system namespace. The
bare snap is one such base snap that provides nothing but a set of empty directories to be used as mount points. This should already be usable if you’ve upgraded to snapd 2.28.
I’m not sure whether it is possible yet for an application snap to ship its own set of libraries/binaries to appear in
/usr. I guess it might be interesting for a snap to specify itself as a base, but I don’t think that is intended with the current design.