The Raspberry Pi Foundation says they are working on providing support for the open-source Vulkan driver for Raspberry Pi.
Vulkan is a low-overhead, cross-platform 3D graphics and computing API. Vulkan targets high-performance realtime 3D graphics applications such as video games and interactive media across all platforms. Compared to OpenGL and Direct3D 11, and like Direct3D 12 and Metal, Vulkan is intended to offer higher performance and more balanced CPU/GPU usage. Other major differences from Direct3D 11 (and prior) and OpenGL are Vulkan being a considerably lower-level API and offering parallel tasking. Vulkan also has the ability to render 2D graphics applications. In addition to its lower CPU usage, Vulkan is also able to better distribute work among multiple CPU cores.
Vulkan support is now common on Android smartphones. Samsung has long supported Vulkan to improve graphics and gaming performance on Galaxy devices. Vulkan is also supported by heavyweight games like Valve on SteamOS. However, Vulkan has just entered the Raspberry Pi, and Raspberry Pi 4 is OpenGL ES 3.1 conformant. Raspberry Pi Foundation wrote:
we still have a very long development roadmap ahead of us before we can put an actual driver in the hands of our users. So don’t hold your breath, and instead look forward to more news from us and Igalia as they make further development progress.