Earlier quoted context omitted.
Probably that Go has to ship heavier runtime (with its own GC etc)
Probably that. Kotlin waited until wasm GC was available and now has a compiler that relies on that. Kotlin wasm binaries can be pretty small depending on what libraries you use. Probably a bit of work but there should be no reason why Go would not be able to do the same at this point.
People tend to think all GC are the same, they are not.