If all major APIs use SPIR-V, does it mean that it could become the ISA of some GPUs? Like that time someone made some hardware that executed Java bytecode directly?

Interesting, so it allows DirectX to use the same shaders as Vulkan? But isn’t the advantage of Vulkan that it has less overhead than DirectX? Does this mean anything for gamers, or does it just make the graphics programmers’ jobs easier when they can use the same shaders for either renderer?