It can since Java 7, the instruction invokedynamic was added for this kind of stuff.
The implementation for Pattern Matching (the project Amber) [1] will use the very same instruction.
[1] https://cr.openjdk.java.net/~briangoetz/amber/pattern-match-...
The language that was supposed to replace Java in JEE and Spring.
Had it not been for Gradle, and there would be hardly a reason to learn it in 2021, other than historical interest.
I see a pretty active community around it and lots of new releases (from the libraries and the language itself) coming up all the time. Your picture of Groovy being dead couldn't be more wrong in my experience.
As mentioned, Gradle is still around.