" The Internet was a lot less corporate than today. A lot of the Internet infrastructure was free to deploy by anybody with a stable Internet connection and sufficient computing power."

You are incorrect there. Internet was hellishly corporate then. All content creation and distribution was owned by major, old-school private corporations. There wasnt even the new-style tech startups like Google which you criticize. Major, incumbent corporations like Time-Warner and its equivalents handed out content and stuff, people consumed them like obedient little customers of 1990s without any feedback.

The IRC, forum scene etc you mention was a fringe. Any of that infrastructure that you could set up yourself could support only a few thousand users per day. Leave aside thousands of concurrent users. They were just fringe communities.

But what they accomplished was creating the culture that created the later startups which carried a lot of the culture in those fringe communities to mainstream. Things like user-first, user generated content, everybody gets everything for free, Open Source etc - all of those come from those early fringe communities, who then created the culture that was adopted by many startups.

Google and similar startups with that new culture broke the dominion of old school corporations with suit mentality who kept the public and customers as obedient takers. They put user in control. Entire internet became user-generated. Open Source became the king. And the world is totally different now. People speak, and corporations have to follow suit. Before this change, it was the other way.

None of these would be possible with that petite infrastructure of self hosted ircs and forums you speak of.