Gearing.

Basically, as the engine is turning at 20000rpm, you can gear it down, and so multiply the torque by the same factor.

The power of the engine is the single metric which you can judge it's peformance by. It takes into account the torque produced, and how quickly the torque can be produced.

The higher up the rpm range you can make torque, the better - power is what quantifies this.