Bah, kids these days who think of 2005 as "early times". I had, in one week in July of 2000, during a road show for my startup, meetings with Lycos, Inktomi, Excite, Yahoo, and a few other search engine companies, all of which were considered strong at the time.

Google was already so far ahead in 2000 that everyone who actually cared used it -- although some people still had Altavista bookmarked and used that because they did not know any better. (The internet-using community was much smaller and more knowledgeable back then; Laptops were expensive and heavy and were used mostly by traveling businessmen, the majority had dial-up internet and AOL was the largest ISP. Essentially all internet access was through desktops running Windows 95 or Windows 98. And Google was already head and shoulders above the rest)

By 2005 Google had such an insurmountable edge that there was barely a discussion. Microsoft started development in what would become Bing before that, and despite all their efforts were never really able to catch up to anything that Google was doing.

Yes, click data helps but really only at the head, where Google already excelled. On the tail the increasing dependence on click data (and later on machine learning and an increased focus on user-specific results) has steadily made Google worse and worse, and Google's supremacy has really only lasted this long because of their page quality measures, which is still a huge problem even now on Bing.

Yeah, not revisionism. Google had better search quality for tech users but Altavista, Lycos, Yahoo, AskJeeves, Excite, Inktomi etc had a better results for general users. So tech users adopted Google and when asked by non-techie friends which search engine they used would reply Google. And then Gmail moat appeared and getting a Gmail account was the highest prestige and everyone was trying to get one.