I am replying to @larry5729 who posted as I quoted.
Just as I am doing you the courtesy to reply to you.
Back on point, another reason why power amps don't have separate power supply chassis is because of the cost of complicated multi-strand umbilicals.
And another, these big chassis take up a lot of floor space that many of us can use more profitably and they should not be stacked because of the heat.
There. Happy now?