This is because not all states have populations evenly divisible by 760000. For example if state A has a population of 1.125 million that would corespondent to 1.5ish representatives, but since there’s no such thing as half a representative, either 1 or 2 must be chosen, and either way it will be disproportionate. With smaller states, the inaccuracy means more proportionally as 2 is twice as big as 1, but 53 is only 1.02x as big as 52.

A similar thing happens with states that have populations below 760000. No matter how disproportionate, states are always given at least one representative, because the alternative of giving them none is insane.

This is why, if you actually looked at your own data, you would find that small states are also the most underrepresented while most big states are near the middle. The house does not benefit small states, it was designed specifically to be as proportional as possible.

There are lots of disproportionate institutions in America, but the house is not one of them.