The JVM also forces one to adopt the JVM's high-level object model and use the JVM's garbage collector. Plenty of languages have a large semantic mismatch with Java, and shoehorning them onto the JVM is cumbersome.

But so far, all those frankenstein hacks still had better interoperability between guest language and java than what you get between the natural peers of js and wasm. It's too early to point fingers that way.