They could come across the http://fallout.wikia.com/wiki/Sierra_Madre_Casino_(hotel). They could come across the Big Empty. They could somehow make that tech their own. My point is the tech is out there! It does exist, an no amount of complaining is going to make it go away. Going back to the key word TIME. In time NCR could find this tech or rediscover it.
Ok so now we know there is post scarcity tech out there wonderful, now let's get a few things straight about all this.
A. Just because said tech exist doesn't mean the NCR has the ability to reproduce it, they barely have the ability to operate Power Armor
B. Even if the NCR CAN reproduce such tech doesn't mean they are going to spend that much capital/taxpayers money doing so
C. The NCR's surplus of labor suprusses private incentives to develop labor saving technology
D. The NCR doesn't even have enough engineers to run a solar power plant or enough forces to clear the thing out, your telling me they're going to waste troops finding and claiming places like Sierra or the Big Empty? Right.
E. The NCR political establishment is uninterested in OSI as shown by the lack of resources for the Vault 22 mission.
F. Give one piece of evidence that the NCR even knows were Sierra or the Big Empty are or that they know what's there.
G. The NCR has limited resources as a nation most of which will be consumed with the easier option of expansion, either into the Mojave, Baja or the Northwest.