I think some of the difference is coordination and spread.
I suppose some gossip could be intentionally malevolent but it's generally not coordinated across multiple mediums and groups.
People also don't generally don't print watercooler gossip out on posters and hang it up in public around their town or state.
Patterns that cause less harm in some context can cause more harm when they're being used by those wanting to intentionally spread misinformation, and when it's much easier for that information to spread to millions of people.
I suppose some gossip could be intentionally malevolent but it's generally not coordinated across multiple mediums and groups.
People also don't generally don't print watercooler gossip out on posters and hang it up in public around their town or state.
Patterns that cause less harm in some context can cause more harm when they're being used by those wanting to intentionally spread misinformation, and when it's much easier for that information to spread to millions of people.