Just to make things even more complicated, there can be a power imbalance at a macro level that favors group A over group B, whereas at a more micro level, there can be situations where the power balance is reversed. I'm a white kid who grew up in a barrio (long story) and I experienced that at an early age. I got the shit beaten out of me many times because my face didn't fit, as well as being on the receving end of disparaging and sometimes threatening comments (especially when I was dating one of the girls from the neighborhood).

So I think you're onto something with the terminological distinctions you're making. Equating "racism" with "systemic racism" gives a lot more truth to the "white people can't experience racism" claim. But along with systemic racism, there's ad-hoc racism and related forms of bigotry that can run counter to the prevalent bias.

Still, if my name were Gonzalez instead of my very common Irish surname, and I applied for a university place or (even more) a job, I wouldn't be at all surprised to be treated more negatively, even with the same qualifications. I've seen it happen to my friends and neighbors.

There's a whole, long discussion to be had about intersectionality, and about the fundamental incommensurability of the many possible axes of privilege and oppression. I'm not motivated to get into that now, but undertanding it makes some otherwise counter-intuitive observations make more sense.

I mistakenly thought they were saying that it's impossible to be racist against white people.

They said everywhere else thinks it's wrong. I guess what I said technically isn't the same, but if everyone thought it was wrong it wouldn't exist. Regardless, my point still stands that it isn't seen as wrong everywhere else either. There are a lot of places where it's seen as normal, or even good.

A certain small, racist faction of white South Africans also uses it, and I've also heard it used in England by far-right idiots.

I don't know where this bullshit incorrect take came from but it needs to stop.

https://www.merriam-webster.com/dictionary/racism

I'm not the one who is confused.

I'm not saying white people are victims of systemic racism, but individuals can absolutely be racist against white people because of their skin color.

When people mean the systemic part, they include the word systemic next to the word racism. You can't just assume it's implied and get pissed when people don't understand your made a last mental shortcut combining two things.

Kinda. You seem to be arguing that one can't be racist against whites because white isn't a race. Do you think that holds that one can't be racist against blacks because black isn't a race?

According to the yapping loudmouths of the manosphere, at least.