I wouldn't put "old people" in the mix - after all, they were already around; if anything ageism restricts what was the established pool. Ageism is enacted to lower wages (young talent is cheaper), not fought.

For women and ethnic minorities, the opposite is true: the more you promote them, as a simple employed worker, the more you're effectively lowering your own wage in real terms. You are effectively self-taxing out of solidarity, while your employer reaps the rewards in terms of additional productivity and profit.

This is one of the problems of modern life for which progressives (including me) really have no answer beyond a generic "all will get well eventually" feelgood optimism. One quick look at statistics for male remuneration and wages in real term post-feminism doesn't really support that optimism.