Ads were terrible, they continue to be terrible, they used to and still do provide most of the money needed to run sites, and it's still hard to get users to pay for content like articles on the internet. We still haven't solved these fundamental problems with funding quality content on the web. There are models that kinda work, but ads sadly seem to work the best in terms of giving everyone access "without paying", even though you're paying with your privacy, time, and eyeballs. Many people prefer this vs something like paywall games or subscription-only services.