I think with the two different types of karting, they both have their own diss and advantages.
For those (indoor) car arenas where you can rent a kart it's too expensive for now. A battery has a limited run time between charging plus they are more expensive then a cheap petrol engine. So you would need more karts batteries and they are more expensive.
In competition karting it's the other way round. Track time is limited anyway and you take away those rediculous tuned expensive engines. Cheaper, fairer, etc etc.