Guile has lots of libraries though, and is the language of Guix. This makes it more likely for people to package their stuff via Guix. Guix itself enriches the ecosystem, and Guile projects can use Guix to make them reproducible.

A few problems remain though. A good debugger, a good macro expander (geiser in Emacs is able to expand somehow), and solving the issues with R6RS library syntax and standard library bindings, are what comes to mind.

Racket's multi-core abilities for a long time were mostly heavy weight (places, starting whole new Racket VMs), except for their implementation of futures, but that one was not always useful. I think recently the situation in Racket has improved, but I don't know, whether it is as good as Guile fibers and futures (which are different from futures in Racket).

Other than Guile as in different Scheme implementations? It's usually not too difficult to port things between Schemes. Especially if you use standard R6RS or R7RS library syntax.