I'm fine doing rounding for the final total. Cheese can still be 6.99 and lunch meat can be 7.49, then when we add it all up, maybe $1 is close enough for a cash transaction. Or maybe we want to still use quarters. Electronic payments can stay ±1¢ because there's no additional cost or inconvenience.

The point is: pennies are stupid. In 1900, they made sense, but that's because in modern terms, you could buy as much for 3¢ as you can for a dollar today.