Yep. Giant superpowered toaster. Useful for ... anything that could do. Which is actually quite a bit.
Best way to reheat pizza for instance. It's nice that they're a little more energy efficient than doing it in the oven, and don't leave it soggy like the microwave.
Not better than stovetop, which is actually best imo, but that takes actual effort.
I reheat pizza in my air fryer in a moderately involved way (but still low effort). Mine's got a reheat setting, which I set at 200 degrees for like 20 minutes just to get it to slightly above room temperature throughout. Then I hit air broil for maybe 1.5 minutes. It bubbles up the cheese and the oil in the crust without causing anything to char. Tastes pretty great, you just have to be willing to wait 25 minutes.
Butter up the bread slices both sides and slap as much cheese as you want inbetween and put the whole thing in there. Flip it at 5-10 mins depending on your temp and device and let it go another minute or two. It takes a few tries to get all the timings perfect and you might even want to do the two bread slices open face with cheese and then slap them together halfway and finish.