The "problem" back then was that nothing required sites to provide a rating and most of them didn't. Then you didn't have much of a content rating system, instead you effectively had a choice for what to do with "unrated" sites where if you allow them you allow essentially the whole internet and if you block them you might as well save yourself some money by calling up your ISP to cancel.

This could pretty easily be solved by just giving sites some incentive to actually provide a rating.