I'd use the analogy of current dynamic language VMs being written C. You're not modifying structs at runtime or creating C functions as a user of the dynamic language. But the creators of the VM are providing as thin a layer as possible on top of that to give the runtime behavior it's dynamism.

There's an often repeated line that WebAssembly isn't really "assembly" and it's not "web". There's a lot of truth to that. I dove in hoping for a cross platform, web enabled assembly. It looks a lot like an assembly but I find it's relatively few restrictions like lack of a true jump command rippling out more than one would have expected. It's also sortuva stack machine and sortuva register machine at the same time.

It does share a lot with the internal VMs in many places like the JVM, Python's VM, .net, etc.