I think there are roughly three eras of the commercial Internet's culture now, and we're entering the fourth:
Through ~2001: Pre-broadband - early web, dot-coms. Everyone got email. If they were more adventurous, they made a home page, got on IRC or Usenet. This era inherited the "US college student with campus internet access" dynamic that dominated the earliest years of the Internet. "The Internet is for porn" etc. There's a lot of overlap between this era and the next one because broadband added so many capabilities that it was like two sibling versions of internet, akin to 8-bit vs 16-bit personal computing.
2001-2008: Web forums, instant messengers, early Web 2.0. A much broader set of people came online and were courted by the new platforms. This was both a broadening and an erasure of any prior history or culture - the "toxic gamer" archetype, the start of influencer trends in various categories(photos, fitness, tech products...), etc. But commerce and community was broadly mediated through "your own web site" rather than platforms.
2008-2020: Post-iPhone smartphones, dominance of centralized internet platforms and algorithmic news feeds. Now the Internet's culture really was accessed by "everyone" and this became clear by around 2012 as more and more social media-driven movements swept through the world. Status-seeking behavior online became very conspicuous, with a ton of activity, styles of messaging, etc molded to juice algorithmic KPIs.
2020 marks the line where we went to full Internet dependence. And... it's also roughly when ordinary people started expressing more agency over how their news feeds should work, and when the really rapid generative AI breakthroughs started. So all at once the blind status seeking of the smartphone era is breaking down, and the new challenges involve finding appropriate sources of truth and filters in an ocean of spam content.