I enjoyed Mark Dominus's blog post [0] about the billing system he cowrote, moonpig. It restates much of the other responses, namely that ignoring infinitesimal errors/rounding would have instilled a culture of - at minimum - doubt. Perhaps another way to see this is to look at a visualization [1] of the discontinuous coverage that floating point gives to the numbers we want to represent.

[0] https://blog.plover.com//prog/Moonpig.html#fp-sucks

[1] https://observablehq.com/@rreusser/half-precision-floating-p...