Maybe nitpicking, but $2400 isn't the take-home wages of $15/hr. Regardless, it seems clear to me that the gov't expects you to have more than just CPP to keep you going in retirement.
Likely because the elderly, as evidenced by the disaster in our senior homes with Covid and care, are not truly cared for by government. Clearly the minimum wage and CPP should match. Far too many elderly living in poverty. Disgusting really, considering.