The way I see it the hey day of offraod electric was much more like gas racing than it is today, In the early days, cars had to race 5min. (ifmar) on 1200 scr cells. Which means not only did motors have to be geared down, if you got out to a big lead then you had to conserve a little power. Similar to Gas and pits stops. Many people restrict there engines and such to get better mileage.
Also before its demise, people ran on WATERED tracks with step pins, There wasn't any soft tires that wear out in 5min. People run 1/8 scale now and tracks are generally watered although since all your electric crybaby pros started racing gas and there is more on the line we are seeing more 1/8 scale races being run with a dry track. buts its still not so bad because a set of knuckles will last thru a 45min main.
Electric racing became very expensive and prototype tires became common at large races and we had battery technology that far exceeds our usage and haven't changed our rules.
So the cycle begain electric offroad died out and everyone started racing the newly invented touring car class because it was cheaper at the time. Now electric touring car racing has gotten so expensive that 1/8 scale offraod seemed cheaper to race at the time, (about 5 years ago) Now 1/8 offroad is getting outragously expensive with $500 engines and blue groove tracks. I am sure you will see electric becoming much more popular when the powers that be stop fearing and start embracing the technology. There is no reason why every electric track in the country hasn't been racing at least 10min. mains. and 15 min. are possible if the people are willing to work with there vehicles to achieve run time instead of all out power.