What is identified as the primary barrier to constructing the Death Star today?

Profound lack of scale in industrial base and energy generation capabilities

While the physics and general engineering concepts behind structures like the Death Star are generally understood, the critical roadblock preventing construction is not conceptual failure but material and energy limitations. Humanity has mastered building small, modular, low-mass stations like the ISS, but the industrial base required to mine, refine, transport, and assemble billions of tons of material is entirely absent. Furthermore, the energy generation capabilities, even for the transport phase alone, vastly outstrip current global output. Therefore, the primary barrier is the sheer scale of industrial throughput and energy production required, which represents a technological gap spanning millennia of accumulated resource management ability.