Gas emissions while fueling is a problem. They’re a significant fraction of the total hydrocarbon emissions.
If you don’t think gas emissions are a serious problem, you’ve obviously never raised a family of teenagers.
Or beer drinkers.
It’s easy to pull the collar where it attaches to the nozzle housing back againsthe nozzle assembly to get more fuel into the vehicle.
Otherwise the nozzle must be mostly fully inserted and shuts off the fuel sooner.
On long-distance, stat, medical bloodeliveries we need to avoid stopping en route.
This also shuts off the nozzle it if falls out of the filler tube.