Why does profit not equal cash flow?

Cash flow and profit are two different concepts.

Profit includes non-cash items such as amounts owed by customers but not yet turned into cash (i.e., not yet paid by the customers). Profit is also net of debts currently owed by the company by not yet paid out in cash by the company (i.e. its accounts payable).

Cash flow simply tracks the movement of cash (actual money) when received and paid out by a company, regardless of whether income was earned or expenses incurred.