> Books that don’t balance to the cent

Individual books, yes (though I am still very dubious of the value in doing this given the guarantees that modern computers/databases offer). I'm talking specifically about cross-department reconciliation where different departments are keeping their own books and have their own data pipelines/etc. They absolutely still have to be reconciled, but there is no expectation of an exact match from the SEC or internal/external auditors.

I agree, mostly. You have to understand the implications of a few cents' difference. One cent (or even one dollar) could be the effect of rounding. Or it could be a single typo. Or it could be multiple errors involving larger transactions with opposite signs.