> And so by presenting your check, which you think is substantially terminating a transaction, you are actually creating a new credit extension with your bank. They are extremely aware that you just asked them to advance you money, even if you are not aware that you did that. They already partially underwrote this extension of credit; that is why you were not shooed out of the building when you originally asked for a checking account.

I'm extremely confused about the usage of the word "need", and the implication that this need for the line of credit is what generates all these downstream problems.

The person depositing a check wants the money soon, sure. And the check bouncing or not depends on the person writing the check. The person depositing the check "should" "just wait"? Like don't extend the credit? Credit card processors hold onto your money for this exact sort of reason!

Yes, there are trust considerations. But don't move money that is not quasi-guaranteed? Pay for money flow? Make the trust relationship between banks and not between atomic actors? Risks are risks are risks but saying that people should be unbanked because their checks will bounce... I guess it's weird to have these pieces of paper have so much trust associated to them in the first place?

Maybe the check network doesn't work as well in this model. Fraud is a whole thing as well of course. I guess in this model people trust checks enough to allow groceries to be paid by check. Just feels extremely suboptimal.