There were WG21 papers arguing exactly to opposite of that, so eh. One big (and IMHO the only) advantage of the async/await model is that the stack size can be

There were WG21 papers arguing exactly to opposite of that, so eh. One big (and IMHO the only) advantage of the async/await model is that the stack size can be bounded. But if you control the VM like in the Loom case, you can expand and shrink stacks as needed, so it is much less of an issue.