Does Vulkan support 2D graphics?
Vulkan is a very low-level API. If your GPU is capable of it, you can draw with it. At the moment it exposes pretty much the set of primitives that core OpenGL does, so if you’re talking about drawing lines and screen-line, co-ads, and things like that, sure. If IHVs have support for real, actual hardware that accelerates 2D better than you could do it with a 3D engine, then they will probably become available as extensions.