Fair enough. I was thinking of the sentence preceeding that: "But why limit the question to the US?"
And as I explained, this wasn't about dismissing racism in the US, which is why people usually mean by Whataboutism, but to explain that the sin of racism is not unique to the US. And contrasting the US with these other cases we see how much the US has moved since then. If people quit acting like what has happened in the US is something uniquely wrong, they might be more likely to see the progress.
It is absolutely not true that slaves "were only worth 3/5 of a person." The Constitution says "Representatives ... shall be apportioned among the several States ... which shall be determined by adding to the Whole Number of free Persons, including those bound to Service for a Term of Years, and excluding Indians not taxed,
three fifths of all other Persons."
This was about apportionment only. And the 3/5 compromise was to deny Southern states representation based on their slaves. Indeed, it was anti-slavery in nature. It wasn't about not trusting the masses. Your link shows far too much bias and not enough nuance. Even your link says:
"The result was the
controversial “three-fifths compromise,” in which three-fifths of the enslaved Black population would be counted toward allocating representatives and electors and calculating federal taxes."
Again, only apportionment, not being "only worth 3/5 of a person."
The northern states wanted only free people--black or white--to be counted for apportionment. The southern states wanted all people--free and slave--to be counted (your link doesn't mention this). The 3/5ths compromise was a compromise to limit southern power and the influence of slaveholding states. Indeed, the slaveholding states did not want direct elections of the president
because slaves could not vote. They had the population, but not votes. It wasn't about not trusting the masses, but recognizing that a direct election or apportionment based on the full population would give the north more power than them.
The 3/5ths compromise was just that--a compromise. And one that is quite reasonable given the time. Had the Constitution outright banned slavery, no southern state would ratify it. Had the Constitution apportioned solely based on population, no northern state would ratify it. The answer was not to make the enemy the perfect of the good, and a compromise was necessary. It worked.