Basically no one would get the glorious single-threaded performance then, since the first time you pip install anything, you're going to discover that it spins

Basically no one would get the glorious single-threaded performance then, since the first time you pip install anything, you're going to discover that it spins up a thread under the hood that you're never exposed to. Or worse, you end up with the async schism all over again, with new "threadless" versions of popular libraries springing up.