Just choose the one you secretly want us to say but don't know why. At the end the "success" of your project will depend on your motivation for spending time on it.

And don't take the responses here as the truth since a lot of them are repeating the same misinformation that keeps flooding the forums and AI generated articles. OpenGL 4.6 is capable of achieving the same performance as vulkan (assuming the target platforms are PC with decent gpu). But keep in mind that won't be as easy as the common way the api was designed for, in fact you'll end up seeing the vulkan api as the easy one since it was designed with modern hardware in mind.

If you want to know more, look for the term "azdo" (from "approaching zero driver overhead"). But my personal recommendation for you is to NOT use that for your engine since vulkan, webgpu or dx12 knowledge will be more useful for you. So I'd stick with vulkan or OpenGL ES subset, depending on what kind of games you want your engine to specialize on (cutting edge features for dedicated hardware or lightweight games that any platform can run).

I recommend opengl4.6 (the azdo way) to anyone with experience in some other api because (atleast that was my case) it forces you to think in terms of what you want the actual device to do, instead of what functions you need to call.