It mostly is though? It's definitely not a fryer. But I agree it still has it's place even next to a convection oven, if not for anything else, then at least for heating the leftovers.
I guess it's like a phone vs a tablet. They have a lot of similarities and a lot of functionality overlap and you could get by using one in place of the other but their use cases are different. Some people may only have one or the other, others may have both and use each at different times for different things. You wouldn't say someone with a tablet has been fooled into buying a rebranded phone.
There’s literally no difference between a conventional oven with a fan forced function and an air frier.
My regular, full-sized convection oven has an air fryer mode. The main difference with the normal convection mode is that the fan runs much, much faster in air fryer mode. Because hot air circulates faster over the food, heat is transferred at a greater rate.