The "documentation" on Hackage is almost universally just the haddock-generated files (which is why it's mostly just function declarations and type signatures).
Most libraries list a "Home Page" that more often than not includes more useful documentation (Haxl's, for example, has the things you've mentioned).
I concur, that most of the time, the documentation on Hackage isn't really sufficient, but I've found that for the most part I just use it to find the homepage, and then go there to read the actual documentation.
I agree that it would be nice if everything was all in one place.
"I agree that it would be nice if everything was all in one place."
I actually find "distilled reference with links to source" a fantastically valuable view. I've no objection to providing some sort of combined view, but let's not lose what we have in a quest for consolidation. I've no idea if that's what you meant or not, and don't mean to put words in your mouth of course, just expressing a concern.
I think fundamentally, Hackage is meant to be a centralized package repository. If you look at other similar projects, there seems to be no real consensus as to whether that should just be a launching-off point to the actual project page, or more inclusive.
When I originally wrote this, I was going to say "It's akin to CPAN", but then to make sure I wasn't misremembering, I looked at a bunch of CPAN packages and saw that they were all actually fully-documented (with examples and whatnot).
I think the advantage to having consolidation is that you can then at least try to enforce documentation standards (whether you should, is arguable). What's super frustrating is going to a Hackage page, finding the link to the project home page (frequently on GitHub), going to the GitHub page and then just seeing a barren directory listing of files.
I feel slightly uncomfortable making statements about how Hackage should be set up however, as it's like going to a soup kitchen and then complaining about the specific soup they've decided to give you. "Oh, you mean this community resource we've set up which allows anyone to contribute a package and have it globally available doesn't provide exactly the functionality you'd like? Please tell me more about how the community can respond to your whims."
Also, for what it's worth, all the Haskell libraries that I make frequent use of tend to have very good documentation (you could argue that's HOW they end up becoming the ones I make frequent use of).
Most libraries list a "Home Page" that more often than not includes more useful documentation (Haxl's, for example, has the things you've mentioned).
I concur, that most of the time, the documentation on Hackage isn't really sufficient, but I've found that for the most part I just use it to find the homepage, and then go there to read the actual documentation.
I agree that it would be nice if everything was all in one place.