If you do not use pedaling on your eBike for most of the time, the following would need to be kept in mind;

The top speed would be limited by the settings on your bike.
The Throttle is meant to be used on flat surfaces or gentle inclines.
If the throttle is applied on a steeper incline your chain or another component of the bike's transmission system may break down.
If the throttle is used more frequently than pedaling the components on your transmission system would wear out quickly and this would not be covered under the warranty.
The biggest disadvantage you would face with a throttle-only ride is faster depletion of the battery capacity and therefore the range would be severely limited as compared to normal estimations.
The motor can heat up rather quickly with throttle only use and can burn out or shut down under certain situations.

Can I use the bike only on Throttle?