IMHO learning OpenGL today just fills your head with outdated concepts, the API is much more confusing than it should be, and error reporting is non-existent.
At least more modern APIs tell you exactly what you did wrong in their validation layers.
Plus, tutorials and in depth guides are much much more common on OpenGL, but that's probably a chicken/egg type of situation.
As other have said, WebGPU is probably the best cross-platform option right now.
(also IME the tricky thing with GL information on the web is that there's a lot of really outdated and sometimes conflicting information around - e.g. worst case is you end up with code that mixes old and new GL concepts without realizing what's what)
And as other have stated the absolutely CRUCIAL question in picking your API, is going to be :
what do you want to do ?
It's was an API they and Firefox presented as a proposal for new graphics API. And it was Google who agreed to follow suit (they had their own proposal)
So in a way it doesn't really matter what these low level APIs are like.
They mostly differ in details like 'programmer ergonomics', design philosophy, and of course platform-availability.
WebGPU is basically the cross section of those three native APIs.
Is there anyone who doesn't despise the Khronos Group?
Meanwhile Vulkan is supported by Android, Nintendo Switch, Linux.
Windows, Apple Platforms, Xbox, PlayStation (aka where money for developers is) couldn't care less about Vulkan.
Will Vulkan replace everything? Seems unlikely considering Microsoft is not dropping DirectX anytime soon, and apple pretty much despise The khronos group, while the web seems to want to go the WebGPU route now.
And openGL seems to simply not die.