The fundamental dynamic that ruins every technology is (over-)commercialization. No matter what anyone says, it is clear that in this era, advertising has royally screwed up all the incentives on the internet and particularly the web. Whereas in the "online retailer" days, there was transparency about transactions and business models, in the behind-the-scenes ad/attention economy, it's murky and distorted. Effectively all the players are conspiring to generate revenue from people's free time, attention, and coerce them into consumption, while amusing them to death. Big entities in the space have trouble coming up with successful models other than advertising--not because those models are unsuccessful, but because 20+ years of compounded exponential growth has made them so big that it's no longer worth their while and will not help them achieve their yearly growth targets.

Just a case in point. I joined Google in 2010 and left in 2019. In 2010 annual revenue was ~$30 billion. Last year, it was $300 billion. Google has grown at ~20% YoY very consistently since its inception. To meet that for 2024, they'll have to find $60 billion in new revenue. So they need to find two 2010-Google's worth of revenue in just one year. And of course 2010-Google took twelve years to build. It's just bonkers.