No way to replace the flavor and texture of a steak cooked over a wood fire. Charcoal comes in a close second. I will say that, in a pinch, an air fryer does a pretty good job if you can get the meat close enough to the heat source when it's time to sear. Same holds true with a gas grill.
Admittedly, any opinion of how to best cook anything is subjective.
Due to the time involved I never do them over wood or charcoal, and I virtually never use my gas grill. I agree with you though, there's something pretty special about steak over a real fire.
Maybe the air fryer would have done a nicer job if I had not preheated the steak. I've been doing that for so many years I don't even know any other way, but it's possible the center should have been cold in order to keep it from over cooking, which is what mine did today.
My typical method is to basically pre-cook the steak either in a plastic bag in a pan of water or using my sous vide machine. Then simply to blot them dry with paper towels and sear them in a cast iron pan over my brewing burner. I've done hamburgers before in the air fryer and they have been perfect, but clearly steaks are not the same thing.