Of course more digits than 2 exists. In Germany petrol/gas has always been priced with 3 decimals. And in B2B it's even more common. I'm talking about 98% of consumer business where the precision is full cents for each transaction.

In general you need to know when to round and to how many digits. But my complaint was that languages have a natural API for binary floating point, which is useful for scientific number crunching, but rarely anything comparable for commercial calculations.

I have not tried to design a natural API for fixed (but parameterizable) decimal precision and the implicit rounding required. But I would be surprised if it's impossible to come up with anything less verbose (explicit constructors everywhere) and less error prone (forgetting to call rounding).