I mean both. And I mean it in terms of plausible variety -- if the area is presented logically, you get very little difference in what you encounter there (and yes, objective would be -- as they are in the latest games -- very close to eachother).
In "one-map" everything needs to be downscaled and to fit in this one specific spot on the map -- there is no possibility to, for one example, plausibly present Denver and Salt Lake City both with different powerstructures, architechture and mindsets as they'd be five minute walk away from eachother, and they'd be smaller than a public schoolyard.
You didn't lack freedom of movability in the original games -- you could go anywhere you wanted to from the get go (but of course at your own risk, as it should be).