Buying vs Renting the home you live in? Please explain why

[William Huston]

Hello All, 

I am trying to make sense of something that keeps being brought up on numerous investment media I have listened to or watched on youtube, but I just don't understand the reason behind it that makes it better. Last night I was watching one of the latest youtube videos from Morris Investing on FIRE movement and he brought up in the live stream that it's stupid to own the place you live in, that it makes more financial sense to buy rentals and rent the place you live. 

Can someone explain the math or reasoning behind this please.