In China you had Zhou, Qin, Han, Sui, Tang, Yuan, Ming, Qing dynasties and modern China today while in Iran you had the Akkadian, Elam, Neo-Assyrian, Neo-Babylonian , Urartu, Achaemenid, Parthian, Sassanid empires and arguably modern Iran today. Even when they weren't at the very top, they were still relevant to other global powers and were kinda always feared that they might "take over".
I can't speak for China, but your geography is all over the place for your Near Eastern places. Half the places you mention aren't actually in modern-day Iran but rather Iraq or even Armenia, in the case of Urartu (an odd choice for this list to begin with). You're basically asking why the entire ancient near east was important.
Really I think you should be asking what is it about that area that it often ended up in the middle of powerful empires, and very conveniently u/Trevor_Culley answered a similar question literally a few hours ago! I'm sure more can be said but this should give you some background for the region: Why have a good amount of Empires (ie Ottoman, Persian, Macedonian) occupied what is now Northern Iraq? : AskHistorians (reddit.com)
The question also seems to imply some kind of continuity to modern Iran. Even if we correct your geography to include Iraq it's a weird way to look at it. The neo-Assyrian empire was destroyed in large part by the neo-Babylonian empire which in turn got consumed into the Achaemenid empire. They were dismantled by Alexander the Great and the region that had been Achaemenid Persia was ruled by Hellenistic kings for a few centuries (I think the Hellenistic Seleucid empire held on to Mesopotamia longer than the neo-Babylonians!) before the Parthians broke off. (Meanwhile the Akkadian empire predates all these by nearly 2000 years!). To me it's kind of like asking if the modern country of Italy is part of the Roman Empire.