Everybody thinks Mag7 scale, but actually it is more relevant if you are a tiny webservice - but available world wide. If you need to match each and every http request from a user half way around the world against a central db, you can't beat the speed of light. If you can do authentication on each downstream server directly using crypto and JWT validation, you at least save that roundtrip to the session db. The revocation list is tiny (a few megabytes tops), append-only, can be public to the world, and thus easy to replicate to your downstream nodes.

If you are a smaller gig, you won't have to bother with replicating your sessions and keeping them in sync globally.