They did it at CERN, but the maximum passenger size is a few dozen femtometers, and collisions are common

I am deeply skeptical as well. But again, if anyone can do it, it'll be CRCC.

I also think it will be incredibly difficult and maintenance intensive to keep any structure that size at near vacuum.

I think there may be a break even point between cost and effect where removing enough air to reduce (but not even close to eliminate) drag is worth the trouble though. Very large clean zone manufacturing facilities are routinely kept slightly above outside ambient pressure to prevent dust/moisture/insects from getting in.