Turn federation off and browse /all. 90% of content is the same 4-5 posters or very niche magazines that are full of posts exclusively submitted by the magazine owner. Comments are a bit more varied but you can’t throw a stone without hitting one of about 7 frequent commenters, which also includes the 4-5 post submitters.
You’re talking about arguing in good faith when your response to his comment about neural plasticity was “BUT WHAT ABOUT PTSD! CHECKMATE” as though you caught him in a gotcha moment and were so excited to dunk on him you forgot what the argument was even about z.
PTSD has nothing to do with the discussion. So all I can glean for this interaction is that you wanted to fight so you could get pissy and block someone.