It totally is enough time to build one. Staffing is more problematic, but if it was a state-run hospital you could've converted a lot of national guardsmen into nurses in the meanwhile. You don't need a lot of talent to handle most Covid cases, just people able to follow the protocol.
Does this have any basis in facts? My understanding is keeping a covid patient alive in the ICU is incredibly demanding.
This is not a "standard" hospital, this is basically comparable to a warzone... so containers, drywall, and considering that most people there don't need a specialist, they can reuse doctors, that have nothing to do during the lockdowns (eg. in my slovenia, government-employed orthopedic doctors had someone else check them in daily, to get paid and get covid extra-pay, while never showing up for work and working in private practy all that time).
I don't think 2 years is enough to just "build new hostipal", let alone staff them, supply them to hospital standards, and start taking business.
It's not land that's short, it's talent.