That's because kbin lacks an official API, which this PR should fix.
I know personally I was looking into modding an old Reddit client to use kbin but found that it didn't have an API so held off. I'm sure there are many other devs that are doing the same.
Running on Windows 11 with a 6900XT and Vulkan and DX11 look effectively identical as far as I can tell but Vulkan runs a lot faster and doesn't stutter when loading a new area.
Unfortunately though it tends to crash on tab out which means I need to use DX11 because I play with friends.