But New Vegas is the frontier, it's still largely unsettled. Of course there's still abandoned stuff, the only superpower in the area for a while only cared about the Vegas city limits. The "clashing of aesthetics" is deliberate here. People still live in somewhat disarray, and an advanced state with manufacturing abilities is moving in. Even in New Vegas, The Strip is in luxury and the rest is destroyed. It highlights part of the class struggle present in the game's world.

New Vegas's (and classic Fallout's) thesis about the apocalypse is "Yes, there was an apocalypse. Nuclear bombs were how the world ended, but it wasn't because of nuclear bombs, it was because of the behavior of humanity." And then you get to see those same behaviors play out again and again, even after the apocalypse. Constant resource struggle, faction alignment, pushing ideologies. "War never changes," etc. There is no shame in preferring a cool wasteland that you get to explore, like in Fallout 3 and 4, but I think it's a tad unfair to point to the clashing of aesthetics like it's a flaw when the main factions of the game are Romans vs WWII America. It's pretty intentional for the story.

And I'm sorry but it is a video game at the end of the day. I'm not fond of wandering for hours with nothing to do or see in my free time. New Vegas has plenty of empty space as it is, in my opinion. It's actually a downgrade (exploration-wise) imo from the awesome worldspace of Fallout 3. Whatever you like is whatever you like, but this has got to be the first time I've ever heard someone say game worlds are better when they're less dense.