Earlier quoted context omitted.
You could flash headlights probably 500+ times before a healthy battery had even a little trouble starting.
We're considering the entire battery lifecycle. So the correct way to think about this change is: More energy required to start engine --> Minimum battery health required to start engine increases --> battery lifecycle decreases.
Yes, if you flashed your lights everytime 500+ times and got your battery to a meaningful low voltage where it barely started every time, sure. But not in the use case presented here.