It doesn't "do" anything right. It just happens to be the oldest university in the US therefore very prestigious therefore being absurdly wealthy (like Oxford/Cambridge in UK) therefore being able to recruit the best talent thereforee being very prestigious.... and on goes the cycle.
In general, it is futile asking what extremely successful outliers "do" right. Even if they wilfully did do something right (which they don't), it would not be replicable.