No, but it was a question for the OP. However, I'm sure your experience will provide good input to the convo above if you're up to share your opinion :)
Ahaha LOL I didn't see the OP. I guess just your question popped up. Well after living abroad 10 months out of last year in 2 either 3rd world country or underdeveloped as they could be labled... I began to breathe differently just getting at the gate to come back to the US and seeing americans. I was so incredibly relieved landing in LA (and kind you I've lived in LA and was so not my vibe). Then it hit me in conversation with my Uber driver who had not gone back to Azerbaijan for 9 years due to visa limitations and missed his family... but when I asked him if he likes it here he was like "what do you mean, I love it here. I don't have to deal with 3rd world stuff". Then It hit me... considering I lived in a third world country the first 20 years of my life, and suddenly I spent all of last year in such... the reason I immediately felt spaciousness was because the heavy thick survival stress induced aura of a third world country's existence reality was no longer looming over me and in my field. I love America and I am happy to be here.
It appeared out of nowhere for me too until I came back and saw it was asked specifically of the OP. I've often (but not always) had the opposite experience when spending time in developing countries. Life might be less convenient, but the sense of reliance on community and genuine vitality of people has always seemed full of life to me. But perhaps that is the danger of being raised in a Western nation then spending time in such places.
Maybe the difference is that about a decade ago I prayed and asked to be guided to a place near nature, with an open hearted community, near water and I found it and spent the last 9 years in a pretty unique counter culture spot in Northern California that has a very close knit many pockets a communities. So I got to experience that in the US and be amongst people where I can be my unique weird mystical self into the counter culture stuff that I am into... I found the same people and vibes in Bali and I enjoyed it there... I loved and I miss flowy dresses and my hair blown wild in the air as I ride my motorbike... but after 3 months I had to run because I woke up realizing I had mold in my brain... ... Found same hippy vibe community in Guatemala but the pollution on every dimension was so bad there that my sensitive being was constantly trauma triggered. ... Now I am actually outgrowing that vibe and have decided to not go back to my community in NorCal for a little bit at least and explore more driven trailblazing vibes perhaps. I do hear you though, most of the US lacks what you describe to a large extend.