Finding renters that makes 3X income to rent

[Qui Van]

Going back to "rule of thumb" I hear a lot is having a renter that makes 3x the rent.  Living in south Florida where rent is already high, is it realistic to find a renter that makes this much?  What are some other ways of screening renters if they don't meat this checkmark when most Americans are living paycheck to paycheck?  Thanks.