It's not dead but it has one big and massive issue that prevents mass adoption - discovery. If I can't just write the name of my friends in search and find them no matter where they made their account - for an ordinary user, or one that comes from centralized services, this seems extremely alien and hostile.

And in the end, if you can't find your friends, you want to interact with, what is the point of using the service?

Luckily, Mastodon is working on a discorvery protocol that should offer a way to find people across the board, which will hopefully make the Fediverse "appear" centralized to the average Joe while maintaining all the benefits of decentralization to the advanced users.