And some of that Cavendish preference is strictly cosmetic. Some varieties will blemish easily but still taste great inside for a while, while Cavendish blemishing means you’ve got 1-2 days tops to consume it.

Yes.

Also also, Cavendish is a "dessert banana". Most banana varieties are more like plantains -- they're savory and are usually cooked.

Shipping, and relatedly, it will mature somewhat after picking. I suspect, much like a tomato, the closer you pick it to ripe, the better it actually is.