"the internet was the domain of white, heterosexual, nerdy, generally well educated guys. And me being a white, heterosexual, nerdy, well educated guy... well... going online felt like coming home. Those were my people"

Thank you for putting it so clearly. Yes, it is completely valid to long for a time where the own niche was the in-group. As someone who's been on the web from early on but a woman, it wasn't really "my people". It was never a safe space for me, but I totally understand where you are coming from. It's great to be on the side of the "default".

The only spaces I genuinely miss are phpbb forums. I honestly believe they are better than reddit, or the fediverse for that matter. Smaller interest groups have a self selection mechanism and better moderation. I think they could still foster a great environment today that would welcome nerdy educated people on a shared interest without specifically speaking to just one type of educated nerds.