[taurknaut]

Old doesn't mean non-advanced. GraalVM is based on a paper (Futamura) from fifty years ago. Off the top of my head I can't think of many language features younger than the eighties—maybe green threading? That would be surprising but might fit. I suppose you could also say gradual typing. Haskell has many recent innovations, of course, but very few of those have seen much use elsewhere. Scala has its implicits, I guess, that's another one.

Personally, I write java at my day job and the type system there makes me loooong for rust.

[pjmlp]

No need for Rust, when JVM has Haskell, Scala, Kotlin, Clojure, Common Lisp.

[taurknaut]

I prefer rust to all of them, but I also come from a very systemsy background. Plus it has the benefit of being much easier to embed inside or compose around basically any runtime you'd like than managed code, which is why I chose rust rather than basically any managed language.

But, it's just a tool, and the tools I choose reflect the type of stuff I want to build. The JVM is extremely impressive in its own right. You're just not going to to find any one runtime or ecosystem that hits every niche. I'm happy to leave the language favoritism to the junior devs—for the vast majority of situations, what you're building dictates which language makes the most sense, not vice versa.