Is it mostly an index you miss?
We generally agree, I think almost all of us believe that SwiftPM should have an index. However, the construction and engineering of a such a thing is very non-trivial. We chose to get started with a distributed model to avoid the need to build an index, and hope that we could add an index later.
I definitely agree that not having an index makes SwiftPM much harder to use than I would like...