Vulkano is a somewhat higher level library which tries to be safe and idiomatic. It looks like it generates its own Vulkan bindings directly from the vk.xml definitions, but also depends on Ash, and this comment suggests that both generators need to be kept in sync so they're effectively beholden to Ash's release cadence anyway.

https://github.com/vulkano-rs/vulkano/blob/master/Cargo.toml...

Maybe they do it that way so they can interop with other crates which use Ash's types?