No.
The energy rating is not reliant on per hour, it’s reliant on per cycle.
The cycle is the constant against which the variable energy consumption of the different machines gets compared.
You are correct in that the cycles tend to run longer, but that’s how the machines save energy (and also in the case of washing machines and dishwashers: water).
The machines do the same task. And the energy rating rates how much energy they use for the task.
Your example, dishwashers:
“After 2010, a new system is used, based on an energy efficiency index (EEI), which is based on the annual power usage, based on stand-by power consumption and 280 cleaning cycles, relative to the standard power usage for that type of dishwasher. For a 12-place-setting dishwasher, an EEI of 100 corresponds to 462 kWh per year.”
Now …
An A+++ machine uses stand-by power and does 280 cleaning cycles.
The EEI < 50 for it means it uses less than 231 kWh (50% of 462 kWh) per year.
An A+ machine uses stand-by power and does 280 cleaning cycles.
The EEI < 63 for it means it uses less than 291,06 kWh (63% of 462 kWh) per year.
The A+++ machine saves you about 60 kWh electricity per year compared to the A+ machine under the terms given for the comparison.
Totally correct.
And an A+++ dishwasher uses less kWh than an A+ one for the same task as per the EEI.
Good, because the cycle time is not implemented in the EEI.
Totally correct. And that’s what the EEI compares (ignoring stand-by consumption as a low factor in this).