This is true in some number of cases. There are absolutely people who could live happy, successful lives if they weren't so busy looking for somebody to blame for their problems. But "racism and sexism and the cacophony of other isms" aren't just about how other individuals treat you.

The percentage of individuals who would deliberately try to hold somebody back on the basis of their race or sex is undeniably small. Existent, but small. But the everyday, less visible obstacles that women and minorities face, mostly based on systems that are "normal" to people who aren't affected by them, are much more numerous. Everybody can succeed in 2021. No argument. The issue is that it's way harder for some to do so.

This isn't just on the basis of race or sex. It's also, significantly, a class problem. But clichés like "live your days empowered and no one can control you," don't apply to everybody equally.