Why were there so many sites that failed before Wikipedia took off? Looks like part of any search engine should be the service Wikipedia prodives, henece, the G

Why were there so many sites that failed before Wikipedia took off? Looks like part of any search engine should be the service Wikipedia prodives, henece, the Google love affair. Can the same model be applied to other things, i.e. User created content + user curated content + indefinite feedback loop: the more users use it the more content is created/curated (a percentage of new users go on to creating/curating content)?