In flat landscapes the e in ebike is superfluous.

It's not superfluous at all. It's been 30C+ in flat London for weeks and my ebike means I arrive at work unflustered and in my normal clothes. There are plenty of other benefits than easier hills.

Only if your goal is to transport yourself. I use my ebike for groceries, typically I'll have the motor in the lowest power setting on the way to the store, then coming back with cargo I'll have the motor turned up. I can bring back heavy bulk items that would have been painful with a pedal bike.