Facebook: Friends are always mutual, and require a request. You can choose which posts are publicly available, and which are for friends.
Twitter: All posts are public, unless you have set your account to private, and then followers will need to request.
Mastodon: Private or public accounts. Every post has one of four privacy levels, which can't be changed later, and there is a multidimensional matrix that describes what posts can be seen by what users from where at what time.
@impiaaa I thought this was a joke post
@impiaaa Do you believe Mastodon was better when:
a) it was all-public
b) it had the extra "unlisted" option that was account-wide
c) it had the extra "unlisted" option granular for posts
d) it had the extra "unlisted" and "private" options granular for posts but private posts didnt leave your server
e) i am tired of making this list
@impiaaa tldr the current system has been a journey and every change was wanted and demanded (sometimes quite aggressively). i think the most confusing artifact is the "unlisted" option but i cant say it doesnt have a use. if i removed it people would be upset, i am sure
@impiaaa and here is the documented matrix: https://mastodon.social/media/t3KPzBNOPBuELLxrgrU
@Gargron "public" does not post to public timelines if it is a reply (unless it is a self-reply with nobody else in the conversation)
@impiaaa That is absolutely not an effect of the status privacy, but the fact that some public timelines have additional filters added for readability. Such as not showing reblogs because it'd be a lot of duplicate content. I concede that this makes the unlisted option useless for replies in practice, but Mastodon's default public timeline filters are not everything. Forks or other platforms may choose different content curation strats.
@Gargron "of that"? Not sure what autocorrect was going for there
@impiaaa I just realized I used absolutely twice in a row in both toots. Sorry about that.
@Gargron Ah, I did not know that public timelines are simply filtered of that.