Lately I'd been thinking about maybe using Rust in places where I might use Go but want better types or performance. The reference types, borrow checker are partially new to me but was easy enough to pick up to use in small programs. The other thing that Go was good for was composing processing as a one way flow of pipelines, I'm sure you could do this with any libraries but Pony seems to be the more direct replacement for Go. Of course there's no ecosystem the size of either Go or Rust but if that's the only reason, using and building an ecosystem seems like the right thing to do for side projects or experiments.