Things change: you can plan and build the perfect city for today needs, it can be built and be that perfect for a bit of time, but can't evolve so sooner or later the disaster happen.

USA/CA suburbs does not work because they are residential-only and you generally need to commute, Rivieras does work far better IF they are not that dense, but in general there is nothing that keep working without changes eternally and as density grow changes became harder and harder. So it does not matter if you feel an USA failed sub-urb or an EU failed dense city or a too dense Riviera: they equally might work for a certain timeframe, than an "innocent & small" evolution at a time and things became ugly, perhaps in different ways, but with equal outcome.

No politicians can solve that, people's can't solve that because they can't always reach agreements.

That's for instance one of the reasons why we start saying since a decade at least that the "really sustainable transportation of the future" can only be by air and where possible by open water: you can change routes depending on needs, while you can't change much rails and roads, at least not with sustainable costs. That's why very few say that urbs aren't sustainable because they are effective for a certain timeframe than needs changes and they can't adapt etc.

Efficiency, resilience and sustainability are not much different than the CAP theorem, you can't have all, you have to choose just two. Seeing Darwin works personally I prefer the last two at the expense of the first one.

Sure, live where you want. That’s the point.