It would only be a partial fix. It will allow async interfaces - but if just "plain GATs" are exposed then those interfaces would transform into something where only Rust language experts know whats actually going on. And the majority of developers are not that, and care more about working on their actual tasks/projects and less about extremely unique features of programming languages (like GATs).

It will also not fix the "lifetimes for async functions are special" issue, due to the lazy evaluation of futures, and the "async functions might sometimes stop executing in the middle" challenge.