Well, I have a hunch the scheme world is moving towards delimited continuations, so virtually free call/cc isn't that interesting anymore.

And the continuations are only cheap in the chicken context. Other schemes with other GC strategies have continuations with a large overhead, but still manage to be faster than chicken in benchmarks that are very continuation heavy.

Chicken is a very nice scheme, with probably the nicest Devs of any open source project, but cheney on the MTA is not magic by any stretch.