Except that Intel's GPUs just don't support some of their functionality on Linux. Like OpenCL. Or a modern OpenGL version.
Right, you might not care, if your usage pattern is mostly about websites and text files. For me, nVidia GPUs are the *only* thing that both brings the functionality I need (as a GPGPU software developer) and actually works.
AMD linux drivers are in a habit of losing functionality over time. Like all functionality (happened to me once). Others have complained that after updating the driver, some parts of the functionality that were present are no longer there. Because of the way Linux kernels work, you usually can't put an ancient driver to a new Linux distro.