minecraft-exported-logs-2024-01-23T17-00-54.log
I tried to load the shader but when it was done loading, the vanilla graphics were still there, no shader.
I have an AMD RX 580

It may not just be the Windows driver for AMD GPUs
I haven't been able to get it to work on Linux either. I'm using a Fury X on Arch.

I'd be happy to provide logs as well if the devs want them.

it's probably fixed in a later version of Iris, but you're on 1.16.5 with an Iris version from December 2022