That compares average mortgage and average rent, but the average house you buy is going to be much bigger (and include a yard) than the average rental. They’d need to compare equal properties to have a meaningful study.
If you compare homes and apartments in the same location, the gap grows even wider. Yes, $4,000 a month in Manhattan is expensive.
But $4,000 might be JUST the HOA cost for buying in the same area. Never mind the 10 million dollar mortgage.
(Spoiler: fake numbers, actually do the math for your city)