This is true, but it's also a really hard problem and most likely any improvements will require enormous scale to implement (because they'll be based on statistical analysis of prior search queries), which only Google and a handful of others have. So no network effects, but huge economies of scale.
Plus, having used some other search engines (DuckDuckGo, Yandex, Bing, etc.), I feel that Google still has a comfortable lead than the competition.