Yes, this is the stupidest thing about an air fryer. Mostly you want to do two things in it for dinner and then one is cold by the time the other is finished.
So you decide you want to make a quick dinner in the air fryer, Lets say chicken pieces or some crumbed meat etc. with some chips. Its almost impossible, one is going to be cold and not crispy anymore. And doing in batches also takes the quick dinner off the table.
Getting 2 air fryers is also not an option as they will use more power than your oven.
Air fryers are for single people or to heat up some precooked food. Here and there just to make chips or a single meat dish, but can never replace your oven or stove.