"White" isn't an ethnicity. Whiteness is a social construct manufactured (and manicured) as a means to enforce the very in-group privilege and out-group hatred you say (and I do believe you) that you despise and oppose. Whiteness is a nebulous and ever-shifting line that allows or disallows membership depending on what most benefits the core members (the ruling class) at any given time, under whatever given material circumstances. “White people have a racism problem. Full stop" is a 100% true statement because whiteness itself is an inherently racist construct. I am confident you mean well and are genuine in your desire to tear down racism, but doing so means recognizing the racism you still, perhaps unknowingly, believe and perpetuate.

But even if we set all of that aside, and go back to that little list you made as a frankly terrible comparison to other poster's correct statement that white people have a racism problem:

“Mexicans/Colombians have a drug problem”
“The Chinese have a genocide problem”
“Black people have a crime problem”

And add to that list the statement you had a problem with. Again,

“White people have a racism problem."

Can you spot the glaring difference? Why one of the 4 items of that list does not belong among the rest? If not, let me spell it out: Mexicans and Colombians (LATAM people in general) are a group suppressed by white people and white supremacist global hegemony. Chinese people are a group suppressed by white people and white supremacist global hegemony. Black people are a group suppressed by white people and white supremacist global hegemony. White people are a group who all benefit from the historic and current suppression of others and white supremacist global hegemony. White privilege is real, and whether one is opposed to it or not, every white person benefits from it.

You mention "tribalism" as being this foundational problem, but looking at it that way misses the most important aspect of the vast majority of conflicts of this world. Tribalism implies groups of more or less equal standing both otherizing their outgroup, but that's not really an issue in the world in which we live, but it does benefit the ruling class when people mistakenly think it is. We don't live in a world of tribes with equivalent power, coming into conflict starting from roughly equal footing. We live in a world of oppressors and oppressed. A world of tremendous asymmetry of conflict. The oppressor perpetrating violence upon those they oppress will never be justified, but the violence of the oppressed against its oppressors in its struggle to free itself from that oppression nearly always will be.

Finally, it is tangential to everything else in my comment, but there is actually one of the three items you listed that also stands out in the list and doesn't quite fit, but for reasons that are... peripheral to the everything else being discussed, but still deserves to be pointed out.

“Mexicans/Colombians have a drug problem”
“The Chinese have a genocide problem”
“Black people have a crime problem”

The nations of Mexico and Columbia do have a problem with drugs being produced in and distributed from their countries, not inherently because of their people but because of the nature of US imperialism in those countries. Despite the sick joke we all know the "war on drugs" to be, it is literally because of the US enforcing drug production in these countries that they have this "problem." It is a problem of US imperialism. Likewise "black people have a crime problem" is also true in that US white supremacy has strictly imposed and enforced poverty on black people, with "crime" (in the problematic traditional sense of the word) is always an issue where there is poverty. So those two list items are problems, but they are themselves rooted in the fact that white people have a racism problem. That middle item in your list though? It is wholly fabrication. The Chinese do not have a genocide problem. I suppose we can still say that item exists because of racism, but where items 1 and 3 do exist in some real sense (but are rooted in the material effects of white supremacy), item 2 is just a grotesque fantasy without any material basis.