Breakers, generators and a dark line
When the power goes, so does the buffet
An induction line is only as reliable as the circuit it sits on. At events, that circuit is usually one socket and an extension lead.
Every induction warmer draws mains power for the whole service. Four on a line, plus a soup kettle, plus the coffee machine, on a temporary circuit is a breaker trip waiting for the busiest hour.
What happens next
Nothing. The pans cool. Someone finds the fuse board. The food has been out of temperature control for however long that took, and a food safety log now has a gap in it.
Outdoors it is worse
A generator: noise, fumes, fuel, and someone to run it. Or no induction at all.
What holds through
A cordless cell runs from its own battery for three hours at 80 °C. A water-activated pack does not know the power is out. Either way the line stays hot while the electrician is found.