the math doesn't add up, what am I missing?

[Amber Linthakhan]

We're in the process of learning everything we need to know before starting to invest but I feel i'm missing something here with the numbers game. I'm looking for lasting, generational wealth by building a portfolio. let's take some easy numbers to show you what i'm talking about...and so someone can tell me what i'm missing here.

Bought house $100,000

Mortgage payment is $800

Rent Charged is $1,400

(minus the 50% rule, the profit is $300)

so the cash flow would be $3,600/year on that one property. 

after years of working hard i've acquired 25 properties., all with about the same cashflow. That leaves me making 90K. 

90K is a great salary, with those numbers it doesn't seem like the vehicle for lasting generational wealth that i expected. Am I missing something?