Neither is US. The empire reference is related to the imperialist state policies. Not the same but similar to that was the policies of USSR with other countries of the Soviet block and what Kzar Putin is trying to do with th Baltic's today.
Your point of view about the Glasnost, Perestroika and consequently the dissolution seems more from the structuralist point of view (which is valid and revelvant for the dissolution), while my argument is more from the economic point of view.
In a very pragmatic way, the closed economy model of USSR imposed many of the issues that deepened the structural problems (like you mentioned) and accelerated the dissolution. Based on Gorbachev own opinion, the Chernobyl disaster was the start of the dissolution: combination of a repressive internal policy creating a fertile environment for corruption, burocracy and inneficiency, together with an outdated industry caused by isolationism.
US seems to be doing the same: closing its economy, negationism, losing diplomatic relevance, ...
Although a completely imbecile, Elon is right in one point: there is only one party in US right now, and it is not even remotely aligned with what the Americans need/desire. Same type of structural corrosion that brought the Soviet block to dissolution.
Saying that USSR didn't extract wealth from other countries in the block, treating them as colonies is a huge stretch. All the political control was crntralized in Moskow, Russia promoted a vast resource extraction, specially from Ukraine, imposed language suppression, cultural assimilation and demographic engineering e.g. Holodomor.