This has been debated for as long as I can remember ( that's a very long time).
Nick Penn has always advocated it but it is not as easy to do for some people as it may be for others.
There is not really one solution that fits all people , which is why in your formative years it is very sensible to seek skilled advice from a good Coach /Instructor.
I have researched and worked on this for many years and can tell you with certainty that some people may always need to occlude an eye to be ultra successful.
Don't get too hung up on whether you can or cannot shoot with both eyes open. Try to and see if it works for you, but shooting with a vision aid or occluder can enable many to shoot to a very high standard.