It was more that graphics hardware got a lot more flexible. Less fixed functionality meant that DXVK (DirectX 8-11 to Vulkan translation layer) was a lot more viable as you were able to emulate old behaviour on the GPU through Vulkan.

Graphics APIs are a lot more „thinner“ these days as well. Creating a Vulkan renderer from scratch is like „first one must enumerate the universe“. But it means that DX12<->Vulkan translation is relatively straightforward, and all the crazy stuff is done in shaders which can be recompiled for different APIs.