Ah well-written OpenGL "emulation" on top of a Vulkan driver is most likely faster than than a badly maintained native GL driver, and you'll only have to worry about the bugs present in the one GL implementation you're linking against, not a variety of bugs across different drivers and driver versions.

Yes, the best scenario of the first case is better than the worst scenario of the second case, but personally i'm more interested on the best scenario of both cases - especially since we already have working OpenGL implementations that take advantage of how OpenGL is specified. I'd rather see a push to improve subpar implementations so they reach parity with the good implementations than throw all implementations out of the window because of the bad ones.