On the Fediverse no, there isn't. The closest thing would be Matrix (as someone mentioned above). But Matrix, while, decentralised, it's not truly part of the fediverse.
So a chat platform is something the fediverse is lacking, but idk how posible it is as federation = less security and less privacy. For example, it wouldn't be able to add end-to-end encryption.
There's Vanilla ice cream, and also "vanilla" ice cream
Burger and sandwich places should offer cooked vegetable options to add to the burger/sandwich for people who cannot eat or simply don't like raw vegetables