True, though for most game/graphics developers you're never interfacing directly with the graphics API, you'll let your chosen engine/library do the heavy lifting.
It does have the downsides of increasing the barrier to entry for custom/bespoke engines but those edge cases seem to be covered well by DXVK.
Right? Dude Vulkan has impressed me a bunch lately. I use it for Deadlock and it feels much smoother than the streamers I see using DirectX, which is crazy since Deadlock is super early alpha. More stuff needs to support Vulkan
Even so, having more software natively supported will always be a good thing. Half the reason why people drag their feet on switching to Linux is because of the lack of support for their favorite software.