@silverpill@mitra.social isn't wrong though, in many cases the posts do mean to be posted in that community.

But it's an expressive thing. I'm able to mention a community like @startrek@startrek.website and it won't be posted there, because I'm only mentioning that community.

And yes, Mastodon needs mention spam to function because otherwise people you reply to won't know they received a reply. It's ... an approach.