Don't blame your lack of promotion on a diversity drive. If the company does not respect you and thinks you are "just a worker cog that is probably a dime a do

Don't blame your lack of promotion on a diversity drive. If the company does not respect you and thinks you are "just a worker cog that is probably a dime a dozen", as you wrote, then you probably won't get promoted whether there is a diversity drive or not. Getting promoted is not really about being indispensable either. I know plenty of indispensable people who don't get promoted. Getting promoted is about proving you are ready to take on more responsibility than you currently have -- leadership of a team, or technical responsibility for more important projects, for example. Expectations will be higher if you get promoted. Somebody thinks you won't be able to meet those expectations. That is what you need to change. When you talk to your manager about this, you should focus only on your own ability to meet the expectations for a promotion. Do not mention the diversity drive or compare your job skills to anyone else's in the company -- that is not going to get you anywhere.