The average household consumption of electricity per day in the US is about 28kWh, which would take around 7-9 liters/day of diesel. Assuming an average US household of 2.6 persons, that's about 3 liters/person/day for electricity alone - does not include gas/electricity spent driving. So, at least for this camp, the average person is using less electricity at the burn, than if we weren't at burning man.
The fossil fuels spent getting to and from the event are more substantial than those burned at the event, but this is a separate discussion I think as to whether or not people should be flying to conferences, events, or taking vacations. COVID was great for reducing travel-related fossil fuel consumption, so we have the data and the experience on how to reduce that, but probably not the will.
The power logs are pretty interesting to look at. On average the generator is lightly loaded, so a lot of energy is going towards idling the generator, but batteries are expensive and these generators are not made to be stopped and started repeatedly.