Rain out months = monthly
membership payments without wear and tear on your equipment.
Massive labor? Modern day express exteriors are not the full serve model from the 1980’s. Many will have 2-3 attendants on site at peak hours.
Not all operators even flip conveyor chains - it can extend life, but only if all other preventative maintenance has been done.
And if you do flip the chain, it is actually cause for celebration - it means you probably just washed 150,000 - 200,000 cars - a good thing.
It’s a tough model to criticize because when it is done well, it is extremely successful. Are they overbuilt? Sure - you bet they are, but there are still locations in high density competition markets that are still turning a major profit. The piece of the pie is smaller, but it is still satisfying.