To me, the idea of a true meritocracy feels about as fictional as a fairy godmother. It's a lovely concept that would imbue many with hope, but the majority of us know it doesn't exist.
Obviously, hard work and dedication are important traits and can only help propel you towards your goals. However, when it comes to open doors in entertainment (or any industry) a lot comes down to who deems you palatable, and whether you hit it off with the right people.
As with everything else, being white, or straight, or cis, or male, helps in the networking process immensely - since other white men still hold the majority of the keys in the entertainment industry.