I've never used an air fryer before, but I have a Cuisinart TOB-260N1 Chef's Convection Toaster Oven and I've used it like an air fryer and it worked quite well. I bought a fryer basket and awhile back I actually reheated some Five Guys fries and they tasted fresh. It's taken quite a bit of experimentation, but I've had great luck making an assortment of frozen food: burritos/chimichangas, popcorn chicken, fries, tots, frozen pizza (have to dial it way back on that one,) fish fingers... I can actually "grill" hot dogs and brats and they almost turn out as well as they do on the actual grill.

I really think it comes down to the make and model (read: high-wattage,) but as I said, I've never used an air fryer, so I can't compare it to that, but we used to have a semi-pro actual deep fryer and I've fried a lot of food. The toaster oven (1800w) does a great job of "frying" things without the oil...

Edit: The toaster oven I have does not claim to have an air fryer feature. I use the convection feature.