"absolutely nothing" is overly strong wording for a plug-in EVSE.
The standardization of the receptacles tells how much current is safe to pull. "This receptacle is 50A rated and can supply 40A continuous" is given by the 14-50 receptacle shape.
But you can buy an EVSE capable of pulling 40 amps and plug it into a 20A rated receptacle. It will happily pull 40 amps until the breaker pops. Most EVSEs that are plug in have adapters to do explicitly this purpose.
The standardization of the receptacles tells how much current is safe to pull. "This receptacle is 50A rated and can supply 40A continuous" is given by the 14-50 receptacle shape.