I haven't thought about it until reading this article. The collecting of random "tiberium", "ore", etc laying around, actually makes sense in the context of Dune. Not so much in Red Alert etc.
I feel like Generals had the best economic design out of any C&C game. Your helicopters / trucks / bare-footed workers simulate modern logistics by collecting crates of resources from a "warehouse". Once they are collected, you can switch to your secondary economy of pumping oil, getting supplies delivered by the UN, stealing money from the internet, or selling goods on the black market.
C&C is pretty much what you get when you want to produce a sequel to Dune II but can't (or don't want to) license the Dune I.P. again so everything has to be re-skinned...
What REALLY set C&C apart was its presentation, which was like nothing else* when it came out. It made a serious and earnest attempt like you were actually using your computer as an interface to command an army*, from the "in-universe" installer to the present day setting where "you" choose a side after NOD and GDI hijack your TV, to the non-western battlefields, to the way Kane and General Shepphard addressed "you" personally in the live-action kinematics. The CD music was awesome too.
* Dune II also was known for its great graphics and having strict system requirements * This continued in later games, but they were much more self-aware.
I think RTS:es with base building is a bit too abstract, nowadays when the graphics are so good, to seem believable, in the way it did in the 90s.