Just the opposite where fire safety is concerned, unless dealing with a hot turbine engine. Lipo batteries have caused far more fires than liquid fueled model aircraft engines have. Even the more flammable fuel gasoline engines have a better safety record.
Modelers switched to battery power not because it was safer, they did it to obtain more power for the amount of mass and weight involved. As model flights are typically of short duration a high output battery-motor combination could be used that was smaller dimensionally and more efficient. Combustion engines are at best 30% efficient where an electric motor can exceed 80% efficiency. Torque response is nearly instant with an electric motor where a liquid fueled engine builds torque more slowly. There is also a smoother power curve with an electric motor because it does not possess the shock impulses of a combustion motor. Remove the shock impulses and a lighter engine mount can be used. Combine torque with propeller efficiencies and faster torque response and you have things of serious consideration in some types of RC flying.
The problem with electric power is carrying the battery weight necessary for long duration flight. An aircraft capable of carrying enough batteries to fly for a couple hours would have to be quite large in size, wingspan, and weight, which is counter productive. That same plane could carry enough liquid fuel to fly many hours at a lower weight using a well tuned combustion engine.
The issue is in finding a balance that can maximize use of available energy densities, at a cost that doesn’t break the bank. This is extremely critical with multirotors as the only devices generating lift is the motors and propellers. When they stop a multirotor has the glide ratio of a grand piano where a well designed winged drone can achieve a glide ratio in excess of 20-1. Those wings generate lift and lift helps carry weight.
