True, but that was not the reason it was abandoned initially.
Back then multi-core CPUs were not much of a thing yet.
The reason it was abandoned is because people were told OpenGL on Windows Vista was going to be implemented through a compatibility layer that was going to be slow.
Even Carmack eventually changed his point of view on DirectX, that is how good OpenGL happens to be.
> First person shooter godfather John Carmack has revealed that he now prefers DirectX to OpenGL, saying that 'inertia' is the main reason why id Software has stuck by the cross-platform 3D graphics API for years.
Back then multi-core CPUs were not much of a thing yet.
The reason it was abandoned is because people were told OpenGL on Windows Vista was going to be implemented through a compatibility layer that was going to be slow.