Where I live we have to pay to the electric grid for the amps on the main breaker. Because the grid has to be able to provide those, needs to be planned accordingly, needs to have the proper diameter cables and transformers, etc. Even if we don't use them. So having 300A "just in case we need it" would be insanely expensive on the monthly bill. This amount of apmeres is more like for a workshop, small industrial or office building
Many utilities will do this based not on the amperage to the house but the peak kw used in a billing cycle - a capacity charge. This helps incentivize reduced peak usage. In your scenario it's strange because you have zero incentive to keep your maximum usage below the breaker amount, other than the per-kwh cost.
I live in the same such country with such rules. They assume rightly that if you request that amperage you will use it and they will plan and bill you to handle it. And yes we then also pay per kWh :)
Why would it be harmful to run at the amperage that I'm buying ? What disincentives do I need?
