I can't speak to the early days of the internet, but for the early days of the web at least, the fediverse is the closest thing we have to the "spirit" of the old web. Everyone running their own things, no central portals, web search was diverse (but not that great). Communities existed not so much on social media platforms, but in the form of webrings, mailing lists and usenet (none of which were centralised).

Web pages were less javascript and css, and more straight html. So pages tended to be static. Images loaded line by line, and often the whole web page would jump around as images loaded if the html didn't pre-emptively set the image size, because the browser had no idea what size the image was going to be until it finished loading it.

But importantly, a significant amount of content was generated by people, not companies. Communities and pages were driven more likely to be created by people with an interest in that specific thing than a company trying to make money, because SEO wasn't a thing.

But AOL, yahoo, google, they all got the idea that there was money to be made by making the search page the gateway through which everything else was found and accessed. And that was a sign of what was to come. Centralisation, predatory trapping of users via the network effect, enshittification... All of it... ALL of it, driven by companies chasing the advertising dollar, rather than passionate nerds making content for other passionate nerds.

It's why I say the fediverse is spiritually the closest you will find to that time period. Communities are driven by passionate nerds, shaped by people interested in whatever it is that they're interested in, and building communities without relying on a centralised platform to provide the infrastructure.