Thats a spam problem and solvable by different means. FWIW I never get such experiences and made internet friends even on reddit via the DM system.

For people to develop friendships with each other, they need to be able to have 1:1 or 1:small time with a ton of back and forth, and public comment sections don't lend themselves to 100 deep message threads. Chat rooms do, chat threads do, and DMs do. In real life it happens naturally as people split off into side conversations.