WordPress core and everything at WordPress.org (the “Meta” environment) is developed by limited volunteer resources.
There are long lists of enhancement tickets waiting for implementation.

If you to to the plugins page and search for plugins, you’ll be using a specially adopted, internal search function. Same goes for theme search.

But, obviously, it has not yet been feasible to develop an internal solution for search all over a large number of language-specialized sites, support forums in many different languages, team webs for different parts of WordPress core, foundation, meetups, WordCamps etc.

I’m quite sure there already is a ticket for this at http://meta.trac.wordpress.org/
if there’s no ticket, feel free to open one, especially if you’ve got resources to develop a much better search solution. You might join the meta channel over at the “make WordPress” slack team. But still: remember that all your peers there are volunteering their time.

Oh. In my view, Google isn’t dumb. If I carefully pick suitable keywords, I’ll often be able to rather quickly find what I need.