I think you're confused about who awards these. Honours are awarded based on decisions made by a committee comprised of the members listed here:

https://www.gov.uk/honours-committees

As you can see, some of them are themselves honours recipients, and some are not.

In no sense is this a self-awarding organisation - and the only reason there are so many recipients on the committee is because honours are given out to just about everybody who has achieved anything of note.