Python has had async for 10 years – why isn't it more popular?

Not too long ago, I read a comment on HN that suggested, due to Python's support for free-threading, async in Python will no longer be needed and will lose out to free-threading due to it's use of "colored" functions. Which seems to align with where this author ends up:

> Because parallelism in Python using threads has always been so limited, the APIs in the standard library are quite rudimentary. I think there is an opportunity to have a task-parallelism API in the standard library once free-threading is stabilized.

> I think in 3.14 the sub-interpreter executor and free-threading features make more parallel and concurrency use cases practical and useful. For those, we don’t need async APIs and it alleviates much of the issues I highlighted in this post.

Armin recently put up a post that goes into those issue in more depth: https://lucumr.pocoo.org/2025/7/26/virtual-threads/

Which lead me to a pre-PEP discussion regarding the possibility of Virtual Threads in Python, which was probably way more than I needed to know but found interesting: https://discuss.python.org/t/add-virtual-threads-to-python/9...

Interesting that very few people in that thread seem to understand Go's model, especially the author of this proposal. If you don't allow preemption, you still have a sort of coloring because most non async functions aren't safe to call in a virtual thread - they may block the executor. If you call C code, you need to swap out stacks and deal with blocking by potentially spawning more OS threads - that's what CGo does. Maybe preemption is harder in Python, but that's not clearly expressed - it's just rejected as obviously unwanted.

Ultimately Python already has function coloring, and libraries are forced into that. This proposal seems poorly thought out, and also too little too late.