The only reason I can think of why a fridge should be connected to WiFi is to notify you if the door is left open, or the temperature is too high.
Digital display for thermostat/thermometer is nice.
Party Mode is convenient when adding large amounts of beverages (or leftovers) as it temporarily changes the compressor setpoint/cycle for a couple of hours in expectation of heavy usage.
Night mode / vacation mode can similarly change the compressor working profile to be either more quiet or energy efficient at times when it’s not expecting the door to open for extended periods of time.
None of these are essential features of a fridge, but they can be convenient.
IIRC, the US measure how efficient an engine burn an amount of fuel, while Europe measure the emissions of the distance traveled.
Quick and simplified example to illustrate the difference:
US car getting 33.5mpg (7.0 l/100km) emitting 126g of CO2 per kilometer. That’s 18g of CO2 per liter of fuel.
EU car getting 39.2mpg (6.0 l/100km) emitting 120g of CO2 per kilometer. That’s 20g of CO2 per liter of fuel.
It’s been years since I read about this, so I can’t remember the details of how/what it’s measured.