Asking for page 10,000 is asking the search engine to search and _rank_ 10,000 * 10 results and give you the last one. That's very expensive and ultimately useless - search is about finding what you're looking for on page 1, not on page 10,000 :)
So it is true that there are 225k+ repositories using Golang (you can compute that with an index scan once a week), but searching them is an entirely different problem.