Compared to electric motors, internal combustion engines provide relatively little torque, over a relatively narrow range of RPM. An typical electric motor can apply its maximum torque, constantly, from zero RPM to its normal RPM.

A gas engine just cannot do that. At low RPM it has little torque and power. At high RPM, you can't really transfer that full power with a transmission in the lowest gear, because now it's too much torque. (Stripped gears and/or snapped belts were pretty common before computer-controlled automatic transmissions.)

This (idealized) chart may help explain: https://www.researchgate.net/profile/Ronghui-Zhang-2/publica...