Ah does not mean it has to be discharged over exactly one hour in some test. It's simply a unit just like kWh. And most batteries are not optimised for one hour

Ah does not mean it has to be discharged over exactly one hour in some test. It's simply a unit just like kWh. And most batteries are not optimised for one hour discharge. There's batteries with insanely high C-rates for delivering a lot of power quickly, discharging in 10 minutes. And some with really low that can standby for years. They'll still indicate the Ah capacity the same way.