I don’t enjoy writing Scala even if the pattern matching syntax is basically the same as Rust. Some of it is the build tool, some of it is the JVM, and some of it is simply distaste for the language.

I don’t hate Scala and I’ve even written a few PRs in Scala, but I have had trouble picking it up for actual projects.

Go is extremely pragmatic and often favors clarity in how code will execute and simplicity in syntax and grammar. It’s basically a GC’d successor to C in many regards. It eschews classes for interface-based polymorphism, it compiles and runs code very fast, and above all, I’ve found it easy and rewarding to pick up.

I don’t want all of the expressiveness of Scala. Just a bit more than Go has today. Not much more.

I think a language that doesn't focus much on backwards compatibility isn't a great comparison to Go :) Having written some Scala, I really like the language. I also like Go's excellent performance, easy concurrency, ability to produce a single binary without having to rely on JVM etc. I think it would be a bad idea to get overly complicated constructs into Go but union types/pattern matching are relatively accessible, not uncommon now and provide a lot of expressiveness without the risk of code becoming unreadable. Those combined with maybe some alternative approaches for error handling will make me want to write Go again (I've written one component in Go that is working perfectly but it was just too much code with bulk of it being err != nil).