I often see those folks that are financially free to purchase their houses in cash so that the banks won't have the interest from paying that for so many years.
While I see the strategy of some rich people that they're leveraging it highly and they're maxing it out so that they can pay less for the mortgage but for longer years and it is their businesses that will pay for it.
They don't want to put out huge cash for it as they'll just have to allocate that on their business to make more money instead.