Theres not really a difference.

In 1995 it was a Usenet newsgroup, in 2005 it was a vBulletin forum, today it's a Twitter or Facebook community, tomorrow, it will be something else.

Facebook and Twitter get tons of hate because they make money hand over fist and founders/insiders become richer than god, (unlike Usenet or forum sites) but the internet has always been this way.

Don't forget about Reddit.

Reddit is designed around grouping people in echo chambers and users come to it for this reason. Facebook may still be more impactful due to the sheer volume of users, but I don't think Reddit's impact is negligeable.

There were higher barriers to entry into those groups in the 90s.

This is true, technology certainly has progressed and lowered the barrier to entry for this and many other things, but my point is that the internet is nothing more than a social network.

Also, you might be overestimating how high the barrier to entry was. There were over 200,000 usenet groups at the peak.

Remember, remember, Eternal September

Yeah, but tech-illiterate baby boomers weren't sharing fake news articles in Usenet groups.

Partly, I guess. The whole internet is a battlefield in the culture war now, though, and even completely unrelated subreddits start banning people who post in the "wrong" places even if they're otherwise following the rules. That and wikipedia is a complete mess now, instead of celebrating what we could build together academics are holding "edit-a-thons" where they tell students to put the lecturer's slant on everything. I have a feeling we might actually be in WW3 and it won't be nuclear, it'll be all about who can distribute their propaganda most effectively.

As an aside, even though HN has a distinct left bias I would say it's definitely one of the fairest forums I've posted on in the last couple of years.