In the near future, Ruby will get a further boost as Ruby’s native interpreter moves to a bytecode-based system and the JVM JRuby interpreter gains the ability to compile Ruby to Java bytecode.

These compilers have significantly improved over the years. A number of factors come into play, to the point where native-code Java execution is on par with other native-code languages, such as C++.

GraalVM 21 has an installable component, called Espresso, that makes it possible to run Java code via a Java bytecode interpreter implemented with the Truffle framework.

Writing a compiler seems like a much harder problem than an interpreter. That might be true today, but I would argue that it was not the case some 60 years ago.