Endlessly, emphatically parroting what is ultimately discriminatory nonsense is an aggressive action against others, not "just an opinion". E.g. [1], and numerous other examples. My favorite, which I'm having trouble digging up the citation for, is a recent-ish study that compared test performance of various minority/gender groups based on social anxiety measures (e.g. "girls aren't good at math")... and found that it was literally possible to turn this difference on and off like a switch based on triggering vs disarming these anxieties as part of the test setup. This literally flies the in face of the schoolyard "sticks and stones may break my bones, but words will never hurt me" mantra so ingrained in US culture. It turns out, we have increasingly good scientific evidence that humans just don't work that way.
Let's be clear about that: being a toxic jerk to {insert out-group here} actively harms those people, and can directly harm their performance orthogonally to their actual potential capabilities. "Yeah, I'm meritocratic in footraces, but only when I can stick thorns in my competitors' shoes."
[1] https://psychcentral.com/news/2010/03/19/negative-effects-of...