Bank takes funds out of your bank account right away regardless it paid or not to the payee. Bank also send paper checks to the payee you selected most of the time. This paper check takes a week or ten days to reach your payee and another same amount of time them to deposit and get cleared, but funds already are made out of your account by your Bank. This cycle gives billions of dollar leverage to the Bank and sell that money for a higher profit, some time back to you also for your home mortgage or so. If that paper checks lost, it takes another hassle to call the Bank to resend the check again to them, but funds are take out from your bank account.
Let’s say; you send a gift check to your family member. This check gets lost, and your family member never complains that thinking you never send it, but funds have already gone from your account, which makes you believe that your check delivered. Now funds are with the Bank, the check is not clear, and your money has taken out from your account. Suppose, if you are sending a surprise check to someone and get lost it via bill payments of the bank system!