I see people make this mistake quite often. They consider their mortgage payment as an expense. Only the interest component of your monthly mortgage payment is the expense. The bulk of the mortgage payment is actually forced savings, much like the contributions to our CPF every month.

After the home loan is paid up, the apartment or flat becomes fully yours. If mortgage was an expense, then the home will not be yours. Rental payment is an expense. After many years of paying rental, you will never get to own the apartment or flat that you are renting.

Many investment savvy people know this, that's why and how they benefitted from property investments.

I have 2 investments properties (both rented out and both not fully paid up) generating rental incomes. The rents are sufficient to cover the monthly mortgages. This is the best or ideal kind of investments. After many years of renting them out the homes become finally yours which you can then sell and pocket the money or buy newer properties.