It's kind of a facile answer perhaps, but I think the answer is as simple as 'you cannot out-Google Google'. The declining quality of Google results seems pret

It's kind of a facile answer perhaps, but I think the answer is as simple as 'you cannot out-Google Google'. The declining quality of Google results seems pretty clear, but only in relative terms. That is, Google now compared to Google in the past. In an absolute sense the service remains pretty great. A confounding factor is that maybe the quality decline is in fact in internet content in general. That is, Google per se is as good as ever, it's just it's become much more difficult to find good results. So, simply, the answer is perhaps that no matter the effort a competitor could put in they simply cannot outdo Google at their core competency. Perhaps for fundamental reasons, but even if not in some niche, surely then for sheer funding and scale reasons when trying to expand beyond that niche. If a competitor to Google emerges, it'll be in some non obvious thing that is not core web search. Basically, when core web search becomes less important and Google can't pivot quickly enough to the new more important thing to compete.