Sort of, but not really. Air fryers have a much faster rate of airflow than any convection oven, which results in significantly faster and more even cooking. The air fryer really is a meaningful technological development.

Smaller volume, slightly bigger/faster motor. Actually looking at the fan there is nothing special with it.

Temperature control is probably hardest part. But in general air fryer could have been done quite a lot of earlier. Maybe materials for the basket is other aspect.

if you consider adding a fan as "meaningful technological development"

Well it is. We had electrical ovens without fan that were great. We had electrical ovens with a fan that were great. Air fryer has much more advanced fan with much more power than earlier.

For me this is how meaningful technological progress happens. It is not like someone one day wakes up and suddenly has rocket that reached space caught back on landing by mechanical arms.

I just purchased my first air fryer summer 2023 — it has changed my cooking life, allowing me to rarely ever "eat out" without much meal prep.

"Just adding a fan" is actually an extremely meaningful tech development.