Right now I can sign up at twitter.com and get to see and talk to everyone else who has signed up - where do I sign up for Mastodon and do I get to interact with everyone else who has done the same?
(the fact that this needs to be explained at all should already be a hint that it will never be mainstream)
The average Twitter user likely does not know what a file is (see: that one iPad commercial where the kid says "what's a file?" or something), and likely uses a mobile device of some kind (tablet or phone) as their daily driver.
Having unusual new concepts you need to explain is a negative point for sure, but that's a world away from the parent comment saying that having any new concept at all means it's doomed entirely.
Twitter had plenty of new concepts with replies, quote tweets, hashtags, threads, ratios. The evidence is that people can figure out this amount of new stuff.
It struck me this is an entirely arbitrary level of knowledge and people have, culturally, learned quite a lot about online computing in the past few decades. You can easily imagine seeing this posted 20 years ago:
"Right now I can sign up at AOL.com and get to email everyone else who has signed up - where do I sign up for social networking and do I get to interact with everyone else who has done the same?"
There's no reason to think people can't come to grips with a federated model just because they're used to a centralized one.
Mastodon is a bunch of separate federated Mastodon instances. In order to see content from several you need to connect to each of them (if memory serves, your identity and social graph are not portable between instances due to the limitations of ActivityPub. This is a problem Dorsey's @ Protocol attempts to solve). That does let you see the illusion of centralization though, sort of like email which is also federated
Mastodon.tech and yes (unless they've been banned)
There's no reason the answer needs to be more complicated than Twitter. Options exist, but in the literal ELI5 explanation people can already figure out "how do I message my friend who uses a different phone manufacturer than I do" without a long detailing of the inner workings of signal, or iMessage or whatsapp
Right now I can sign up at twitter.com and get to see and talk to everyone else who has signed up - where do I sign up for Mastodon and do I get to interact with everyone else who has done the same?
(the fact that this needs to be explained at all should already be a hint that it will never be mainstream)