I spent my 60 years in the US in suburbs. I grew up in Fairfield County, CT and spent my adult life in the San Francisco East Bay. I get that this is an American-centric survey and list but the general question is about the retirement desirably of livable cities. I found that as a retiree I absolutely love living in a big city for the reasons mentioned.
I moved to Bangkok, Thailand. OK . . . I get that moving abroad isn’t on most people’s list of things to do but the general characteristics of city living apply. I live in the very center of the city. Yes, Bangkok has big city crowds, noise, pollution and it’s pretty hot here but nothing particularly different than the city issues in the cities listed in the survey. I lived my first 6 years here in Bangkok without a car (I have a car now). The infrastructure here is modern and amazing. There are great hospitals actually walking distance from where I live. Grocery stores, fresh markets, and restaurants are within walking distance or an easy ride on public transportation. It is an exciting place to live vs the quiet of the countryside and exciting is what I prefer - it’s a personal choice. (moved here when I was 60 and I am 70 now). It is also very safe here, day and night. I’m not saying there is no crime here but compared to having my car windows smashed 3x in 3 years in the East Bay then yes it is safe here. Thai culture is very non-confrontational and that contributes to the daily sense of safety. The cost of living is lower but that is more complicated in the sense that it depends a lot on personal lifestyle choices. In general though, I have what i would characterize as an upper middle class lifestyle at 40-50% of what that would cost me in the SF Bay Area. It’s certainly not more expensive to live in Bangkok or Thailand in general relative to the most places in the US. Even with the low cost of living though it helps to have money.
There is a great international expat community here. My social life has improved since moving here.
I have lived in the rural Thai countryside. None of the convenience of the city and I would assume the Thai countryside not too dissimilar to living in the countryside anywhere. Mid-size cities are of course in the middle.