Actually, it’s better to borrow the million WHEN you have a million - so as to keep the million earning money for you in interest or investments.
;-)
What if, instead, you paid a million CASH for your house, and then put the money you WOULD have been paying out in mortgage principle and interest each month for the next fifteen or 30 years into investments? In pretty short order you'd have your million back and earning 10% again, AND you'd have a paid-for house!