The number of people wanting to create pages about everything is lass than the number of people willing to maintain pages about everything.
Thus, assuming no vandals or spammers ever create pages, you have very many pages created, and not so many people available to check and maintain those pages. Over the years spammers and vandals insert some changes. Or the information just becomes out of date.
So, now someone has to pay to store and host this stuff, which is not ever used by anyone, and which is out of date or full of links to handbags and shoes and medication, or with "BOB IS GAY LOLOLOLOL".
Thus, assuming no vandals or spammers ever create pages, you have very many pages created, and not so many people available to check and maintain those pages. Over the years spammers and vandals insert some changes. Or the information just becomes out of date.
So, now someone has to pay to store and host this stuff, which is not ever used by anyone, and which is out of date or full of links to handbags and shoes and medication, or with "BOB IS GAY LOLOLOLOL".