A couple of things happened. First of all, there are a lot more people on the internet. Like a lot more. And that means different preferences, age groups, nationalities, etc. While previously you could pretty much guess, nowadays that's impossible.

Second. It has become a central part of people's day to day lives in ways that it wasn't in the early tens and earlier. The bulk of people's engagement shifted towards mobile apps. That meant a lot less talking and a lot more scrolling. Consuming a lot more content.

Third. Content has become the means to earn money. That meant a large shift in the way content creators thought about what they made. People started to go for safety, copying what worked, experimenting less.

Lastly, we lost a lot of curators. Most of the curateing is now done by algorithms. Blogs and curated sites have died. Back in those days most of the content you went through on the internet was lists of what other people had found. There were few alternatives.