Local documentation does not exist anymore, in a practical form.

You need the official docs plus countless other resources from other people and for a relevant version of your software.

Gone are the days a few books and a computer was all you needed.

Your compiler is spilling out some weird message? Go scavenge the interwebs for someone who figured it out or spend your whole weekend in that.

If you can't understand the messages from your complier or need other resources from people that you can't find in the doc, either the language/compiler you are using is crappy and you should use a real one, either you aren't a developer but a copy/paster that pretend to be one.

someplace like http://devdocs.io goes real far

not practical

How do you think developers built programs pre google/stack-overflow? i.e. early to late 90's.

It was hard and less people did it.

The people who declared themselves developers/programmers weren't just serial copy/pasters that is for sure.

And now it's easy and we're drowning in endless webby and cloudy cruft.

Exactly, when my car doesn't work I just ride one of my horses /s

A shelf or two full of books and magazines and generally much more slowly.