@Jakobiner This brings up a number of additional questions and issues.
I default all my toots to "unlisted" (a partial compromise to my CW aversion). Scope may be individually toggled broader or narrower.
Hashtags aren't searchable unless toots are public. I find this a misfeature, but will toggle scope to global when including hashtags meant to be searched.
People will occasionally toot personal matters followers-only. Given my followers list all but certainly doesn't match theirs, any reply other than a DM strikes me as ill-advised. (Stepping in on such discusions should usually be with extreme sensitivity regardless.)
Thread scopes generally should be no broader than the parent or any subsequent upstream toot. Note that the "public" vs. "unlisted" distinction isn't one of scope, strictly, but of amplification. And searchability.
"Followers only" especially seems ill-advised. Unless a profile is locked, this is not directly controlled by author, different users' scopes effectively never intersect, and determining just what scope is is effectively impossible.
The design and consequences strike me as a bit of a mess.
And as noted earlier, the Federated stream usually has limited utility.
On the internet, everyone knows you're a cat — and that's totally okay.