Drilliing many holes needs energy delivery = watt-hour delivery = voltage x amp-hour delivery
Fast drilling of holes needs power delivery = watts = volts x amps = high (rpm x torque)
This example Ragone chart
shows that, for a battery of a given weight, you can't have a battery optimized for power delivery and energy delivery at the same time, so you are kind of forced to decide which is more important.
If weight is important, this same chart can steer you toward a weight/energy/power tradeoff.
The trick is to find a chart showing all the battery technologies commonly used today in cordless tools.
In the event of a tie between tools, for which do you get the more w or w-h or the less weight, per dollar spent?