Additionally, Mastodon working well at the current low scale doesn't tell us much. We don't actually know how reliable it will be if it ever reaches X scale.

X has failed in a way that endangered lives, and in way that will likely persist. Mastodon has yet to be tested. It seems logical to start testing Mastodon's limits in earnest.

Mastodon has massive Japanese communities on it, Pawoo (social that was owned by Pixiv, was the largest Mastodon instance before Musk took over Twitter, now it's second), mstdn.jp (used to be second, now third), now there's also Misskey, which is not a Mastodon instance, but it's perfectly compatible with it.

Mastodon was battle-tested by the Japanese, almost no one used it seriously before them.

We have a similar situation for public transport here in Hamburg. The status updates for outages on the S Bahn network are only available on X, if you don’t have an account there there’s no where else to see it