He was talking about JVM specifically, part of the benefit of WASM is portability, CLR is getting better in this regard with .net core but that's a recent devel

He was talking about JVM specifically, part of the benefit of WASM is portability, CLR is getting better in this regard with .net core but that's a recent development (I don't see how phone VMs compare) CLR also has an object model and a memory model that's not very friendly to unmanaged languages, hence C++/CLI, and the runtime is not very lightweight for embedding purposes