We should not feel superior, the Boeing Dreamliner presented at its premiere was not much better. It flew but lacked any interiors or anything but basic avionics. Now it sits grounded because of the lithium batteries that like to catch fire. It doesn't mean that the Iranian stealth fighter is fantasy. Quite the contrary, most countries unveil mock-ups to prevent secret technology from being unveiled. The reverse happened to the US. The F-22 flies and is operational but has the unfortunate habit of depriving pilots of oxygen. It got so bad that pilots started to refuse flying in them. The oxygen generator has been fixed but it took many months to fix something that should never have been a problem in the first place.