If this BBC story doesn't indicate that there is an overreaction to new Twitter management, I don't know what will. It reminded me of when I was considering trying to move all of our customers to receive PGP encrypted mail in 2005. An intelligent employee brought up that an average business person would never do that. Luckily we never implemented it. Mastodon is great but it isn't a replacement for Twitter. Too much…
You seem to think Twitter is for journalists. It isn't. It's for anyone who wants to use it, including people who have the time and energy to figure it out and no need for "reach". And that's more than enough.
What people fail to understand about Fediverse apps is that they aren't trying to be big. They're trying to stay small but be part of a big, connected universe. Mastodon won't ever be Twitter but it could still be incredibly useful.
Also note though that this doesn't mean Twitter is safe. Twitter's main rival is 'nothing' - eg users realising they don't want to use or read a microblogging service. People quitting Twitter because they don't like it any more is a far greater threat to Twitter than any fediverse service could ever be. Elon can happily ignore Mastodon. He can't ignore breaking Twitter (if he is, which isn't certain at all.)