The reason I'm asking is Buffie suggested that half of the...

The reason I'm asking is Buffie suggested that half of the investment loan was going to be paid off by renters in 20 yrs time. I wanted to understand how he came with that conclusion, since rental income was likely to only service the interest only component of the loans. He/she talks about 80/20 depending on where and price of property, is rental income sufficient to contribute to amortization? let alone servicing the interest payment on top of all other landlord costs - since he also talks about negative gearing.

"so in 20 years you have turned 200k into 3.4 million dollars (1000%+ increase). And during this time people renting out those properties will have paid half of them off for you so theres another 1 million dollars"