Unless you have all of the optimizations available to the lowest level you are restricted which is why people complain about "only JS".
There are no optimizations missing from x86 so complaining about it is pointless.
Especially given the improvements in sandboxing having a more powerful underlying language could improve things (note that this doesn't mean it needs access to the API of the underlying OS, which is where Java got itself in trouble).
Unless there exists a way to peel back that layer it is immaterial. Asking for something that doesn't exist is different than asking to have access to a layer that does exist.
There are no optimizations missing from x86 so complaining about it is pointless.
Especially given the improvements in sandboxing having a more powerful underlying language could improve things (note that this doesn't mean it needs access to the API of the underlying OS, which is where Java got itself in trouble).