> One key part of how async/await works in Python is that nothing really happens until you call await. You’re guaranteed not to be suspended. Unfortunately, recent changes with free-threading make that guarantee rather pointless. Because you still need to write code to be aware of other threads, and so now we have the complexity of both the async ecosystem and the threading system at all times.

I don’t understand how free-threading changes things here. In a multithreaded Python program without free-threading you might be preempted at any point before calling await at the granularity of the GIL.

You are right. It's just that multithreading before free-threading was too broken and too slow to the point that very few people use them for high-traffic production things. And people decided to write it like NodeJS to further handwave the problem.