While I haven't taken the leap to using a JWT in any of these cases yet and am a little bearish on them, I do also feel like the baby goes out with the bath-water, here.

Nothing about adopting JWT says you can't still use a full auth check for state-changing endpoints, and use a stateless session to shave some evaluation time off of frequent read-only requests for data that isn't terribly sensitive.

You probably shouldn't do it lightly or prematurely since it makes it harder to reason about authentication, but I think it's worth considering whenever you're optimizing.