Surprisingly well, I think. I haven't heard any updates in a couple months (and I don't see it on her blog) but it sounded like Alyssa Rosenzweig had hammered out an early compiler and started working on a graphics driver itself.

https://rosenzweig.io/blog/asahi-gpu-part-4.html

At the launch there were various pronouncements that "it'll never happen, Apple will have locked it down so hard it'll never go anywhere" and the more optimistic "there should be a start in a couple years" and at this point I wouldn't be surprised if there was something alpha or pre-alpha grade that you can toy around with by the end of the year (my words not hers - I have no relation to any of the Asahi Linux efforts).