I think that's revisionism. Social media existed before online advertising. Usenet was quite massive and vibrant, countless IRC servers were maintained by volunteers, web-based forums covered pretty much the same ground as Reddit does today. All supported by the goodwill of individuals, non-profits, and businesses such as ISPs that actively wanted the internet to be interesting because they were making money by selling access to it.
The thing that changed in the mid-2000s was that we found ways to not only provide these services, but extract billions of dollars while doing it. Good for Mark Zuckerberg, but I doubt the internet would be hurting without that.
The internet was absolutely better without that. I arrived after the original Eternal September, but there have been more and more until now everyone is perpetually online 24/7.
Now fucking everything about the world is a hustle to monetize every possible nook and cranny around content. There isn't even content anymore, it's nearly all AI slop as a substrate to grow ads on.
I am nostalgic for the era when I found "punch the monkey" irritating. People used to make websites as a labor of love.