1. A defect report is not a proposal. Proposals may be used to resolve a
reported and accepted defect, but you don't write a proposal for both the
defect and its proposed resolution. Before you put a proposal together to
resolve a defect, that defect has to actually be *accepted*.

2. This is not a defect in the standard. If atomic were intended to be a
foundational technology for the implementation of all thread
synchronization primitives, then it might be considered a defect. But I've
yet to see any citation from proposals that suggests that this was ever the
case. You *personally* may think of them that way, and thus it's wrong for
them to fail to achieve that. But I don't see where any of the
atomic_notify* stuff was ever intended to be something that could be used
to build up all other synchronization primitives.

3. P2616 seems to do something similar, but it wasn't adopted into C++26.
You might want to investigate why that is.