But this approach would async-pollute all the sync calling functions right? if I had a call tree like function A(){ B()} function B(){ C()} ... func

But this approach would async-pollute all the sync calling functions right? if I had a call tree like function A(){ B()} function B(){ C()} ... function Y(){ await? Z()} async function Z(){...} Then A-Y would need to become async. If await Z() was allowed then we could avoid this. So is there a reason why it could not be implemented this way?