The point is that you probably don't want a truly stateless backend.
What you probably want is to store a small amount of critical state in a very fast, very scalable KVS, allowing most of the backend to be stateless.
So much of the discussion around JWTs boils down to "I want a stateful backend, how do I use JWTs for this?" (Answer: Not well. Why use JWTs?) Or "I have implemented a stateless backend, I'm using JWTs, how do I work around the limitations inherent in being stateless without adding state?" (Answer: You can't. Why are you using a stateless backend?)
What you probably want is to store a small amount of critical state in a very fast, very scalable KVS, allowing most of the backend to be stateless.
So much of the discussion around JWTs boils down to "I want a stateful backend, how do I use JWTs for this?" (Answer: Not well. Why use JWTs?) Or "I have implemented a stateless backend, I'm using JWTs, how do I work around the limitations inherent in being stateless without adding state?" (Answer: You can't. Why are you using a stateless backend?)
That being said, if you really DO want a JWT replacement: PASETO, Fernet, and Branca are all possibilties. See, eg, https://www.scottbrady91.com/JOSE/Alternatives-to-JWTs There's also Macaroons, but I don't know much about them (http://macaroons.io/).