> The tax of supporting multiple APIs is not always huge. I recall reading that Unreal's Vulkan support was done by 1 or 2 employees.And because of that, we still don't see full Vulkan support there - it takes time to implement. See https://trello.com/b/gHooNW9I/ue4-roadmap (search for Vulkan).
If anything, it highlights the tax, not disproves its existence.