It seems like people that are highly engaged in online conversations do so because they, consciously or not, think their contributions will pull the universe toward some goal. That goal might be "truth", "freedom", "absurdity", etc. (Uncovering those goals sounds like a really fun project.)
I think some of it also comes from status needs. Specifically, dominance.
I don't understand the lurker mindset whatsoever. It has to be how most people interact with the internet though, otherwise there would be 10's of thousands of comments on every post here. Ever since I started using the internet as a little kid I've felt the need to toss my thoughts into the cyber stream. I think all the word games I've played with other people online have truly made me a multitude.
All that is opposed to real life interactions. In real life, people sometimes just sit next to each other and occasionally share thoughts. It's a lot more like chat rooms instead of like social media. In a chat room, the facets of an individual are more prominent, meaning, as the chat continues, you witness how a person reasons through their ideas and feelings. Maybe he's a climate skeptic but oh hey, you love my favorite band, what!
The above multi-facetedness of irl and chat interaction is in contrast to this, what we're engaging in now. This comment I'm writing is an expression of a microscopic slice of time in my life and thoughts in my brain. But it's now reified. People can come back to it 10 years from now and play with it in their heads. I might be dead by then, or I might be a fascist or I might have become a Zen monk. The new eyes sipping my words have no clue, little context, of who I was an hour or a day ago, let alone a decade since.
No wonder we stumble into toxicity on social media. Not only are we probably trying to prove or achieve something, but its asynchronous nature causes weird second-order effects. Millions of people can read a Facebook post written in a fit of rage and fear with a migraine ripping through the body of the author at 3 in the morning, but suddenly, that psychologically, philosophically, sociologically, cosmically absolutely insignificant moment could cause ripples throughout the entire world. We're built by evolution to play joyous semantic games with each other. With social media we're trying to do the same, except our innocent flourishes are all punctuated with grenades and nuclear bombs.
Anyways, those are my thoughts on that. I'm very happy to hear that you found good people to share your esteem and friendship with. That's the dopest shit.