Your opinion does matter. Why?

Because the more straight, white people say they want diversity, the more studios will perceive it as financially worthwhile. This means more stuff will be made. Studios don't want to produce stuff that they perceive only appeals to a tiny minority because they are, after all, running a business. They do need to make money and pay everyone.

(Ideally more so we get this strike resolved quickly. Ahem).

Publicly saying you watch diverse stuff helps. It really does.