Noise, fumes, fuel and a person to run it
Outdoor events on induction mean a generator
There is no outlet on a lawn. Induction outdoors means hauling a generator and everything that comes with it.
An outdoor buffet on induction needs power. That means a generator, positioned where guests will not smell it, fuelled, started, and watched by someone for the duration. It means cabling across grass to a table, guarded so nobody trips, and a distribution board that can take the load.
The failure modes
The generator runs out. Someone kicks the cable. The board trips. The line goes cold and the caterer is searching for a jerry can while the guests queue.
What outdoor looks like without power
Cordless cells charged in the kitchen and carried out, holding 80 °C for three hours. Water-activated packs for the delivery drop or the short reception. A cold cell at −10 °C for the seafood and the dessert. No cable, no generator, no one watching it.