Twitter and Reddit may have only lost a few million users to Mastodon and Lemmy so far, but these are nation-sized numbers, comparable to what Scandinavia is to the United States of America. The incumbents have allowed the fediverse to reach critical mass. It's only gonna get bigger, but it already works well enough that I've no need for any other social network. It's nicer here.

This resonates with me. Although they are still lacking for the long tail of small niche communities, Lemmy and Mastodon now have enough people and content that I rarely find myself going to Reddit or Twitter. The fediverse is not perfect and there is a lot of room for growth, but it is now large enough to be viable and hopefully sustainable.