I have as well, and that's why I have my opinion that they aren't squalor, at least not guaranteed. I lived in one crappy apartment when I was in college because it was dirt cheap. After I got a job, I spent maybe 20-40% more on apartments up to my last one (which cost a lot more, but was in a great location for me, walking distance to my MMA gym and all my hangout spots). None of them were crappy, I rarely heard my neighbors. And the only truly obnoxious neighbors were evicted after the police were called for a combination of noise and indecent exposure (their guests went skinny dipping in the apartment pool).

I live in the suburbs now, and with regard to noise it's no better than the apartments except my first crappy apartment, and the brief time next to the obnoxious neighbors. My next door neighbors on one side are great, on the other side they're dicks and fight constantly and loudly. Across the street are two houses one with a muscle car and the other some kind of loud motorcycle, both are project vehicles. So I get to hear them revving their engines in the evening (too early to warrant filing a complaint, but still very obnoxious).

There's nothing magical about apartments that make them bad, or houses that make them good. The best you could hope for with regard to general quality of life (particularly noise and pests caused by poor hygiene from your neighbors) is to live in the country hundreds of feet (at least) from neighbors with trees in between. But then you forfeit access to everything else since nothing is close without having to drive.

I do not care if you choose to live in a single family home or a unit in a multi family building. The issue that we have is that "single family zoning" where the maximum density allowed on a plot of land is a single house is a land use pattern that it is a government restriction that subsidizes homes for the well off at the expense of everyone else. In a world in which central city land that is currently zoned SFHs is rezoned for multi family dwellings, the price of SFHs would rise to meet the true demand, while the price of a "living unit" in the area would fall due to the land required per dwelling unit decreasing.

Yeah it was never about squalor for me, but unless you are in a million dollar condo with top notch sound proofing in every wall you will hear your neighbors at all hours and everything they do. Some people may love this, but I hate it. How do I know? I lived it the first 30 years of my life until I bought a house in the burbs. My quality of life is so much better now. No I didn't buy a McMansion. I have lived in bigger apartments, however I have space and nice solid walls between myself and neighbors and it's a huge % increase in quality of life not to hear other people's sex, family quarrels, or bad taco bell incidents at all hours.