> [Async has] Huge disadvantages with absolutely zero performance gains for 95% of programmers.

One curious thing is that Java has elected to use lightweight threads instead of async methods: https://www.javacodegeeks.com/2019/12/project-loom.html

Their arguments are compelling:

- Works with existing debuggers and debugging techniques.

- Stack traces aren't polluted with irrelevant garbage.

- Doesn't create method apartheid, where async and non-async can't "mix".

- Doesn't force library authors to "buy into" the async model.