OpenGL support isn’t there at all for Meta and Pico in 5.1.
And in 5.0 you can get OpenGL to work on the non OpenXR paths with forward shading off and a very narrow set of render settings.
And Vulkan wouldn’t be that big of a deal if High Resolution Video Playback (2K+) didn’t have a large performance impact. That’s assuming all else is well with Vulkan the video playback performance alone is enough to stop certain projects in their tracks when using Vulkan.