Agree with the latter portion of what you are saying. But did you play DOS2, specifically the last two acts? Larian always posits a lore or story-based reason that densely populated areas or functional civilization are suddenly absent, like the conflict on the Nameless Isle or the Siege of Arx or the various troubles on Reaper's Coast. They turn "civilization" into urban wilderness, and safe "neighborhoods" or boroughs into village equivalents. There's not actually a world that feels lived in because it's all a crisis waiting for you to show up so they can hit the "play" button, like Waukeen's Rest.
I actually ran out of steam with DOS2 near the beginning of Act 2, so haven’t seen the bits you mention. (I will get back to it one of these days, though it took me three tries before I finally managed to get to the end of DOS.)
I can understand why you are wary on the basis of DOS2, and the early part of BG3 obviously won’t have given you any reassurance that it will be different. But they’re now a much bigger studio so have the resources to do more, and surely they know there will be HOWLS of disappointment if we don’t get to explore a functioning city as we did in BG1 & 2. I’m going to choose to remain optimistic until reality forces me to be otherwise

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