I often hear people say that PLO5 has bigger variance than PLO4.
Why is that?

My first thought was actually the opposite: if the equities of the starting hands are closer in PLO5, shouldn’t that reduce the variance?
Of course this assumes you’re better than the field — but if the equity gaps are smaller, then the starting hand matters less and postflop skill becomes more important.

Am I thinking about this the wrong way?
(I probably am, since everybody keeps saying PLO5 is higher variance — I just don’t understand the reason.)