[0] https://en.wikipedia.org/wiki/Old_Man_River%27s_City_project
I suppose on the ocean would be interesting if it were tied with some desalination and generally using the ocean sustainably.
One way to kick that sort of thing off might be individual, modular units which could be brought together to make ever larger complexes.
- Variety of building age/quality, to have rent levels that allow diversity of activities (low rent hole-in-the-wall for an art club; high rent, new construction, ground floor retail for luxury shopping)
- Variety of building use schedules to ensure eyes on the street at all hours and full utilization of infrastructure (including restaurants). A pure residential area or pure office park will fail this and turn into a ghost town at some hours. Hudson Yards might hit 2 schedules but not 3, which is the ideal.
- “a dozen dozen places in a five minute walk” allows niche businesses to survive, since the large effective service radius includes enough people to find some customers. Rockefeller Center’s arcade is actually quite important and covered in the book, since it cuts some too-long blocks into short enough blocks.
I don’t remember the fourth condition, so read the book to find out.
The thing is, there cannot and should not be another new york or manhattan. We need future cities to be energy efficient, sustainable and defensible. A city that would last the next two or three centuries allowing our current culture and history to be passed on is important and I am not sure cities like new york will be pleasant to live in by the end of the century nor are they or will they be cheap. That said, there many millions of people and they can still continue to live in existing cities but we can't just keep building more LAs and NYCs or continue to pretend homelessness, high rent/house prices, the ridiculous infrastructure required to support cars and the ever depletion of agriculture friendly land and sustainable water are not a problem. Now is the time to fix them not when famine and disasters are killing millions.
But to counter your point about mediocrity, vegas is a good example. I have terrific food and entertainment there despite the seemingly endless interconnected structures of hotels and casinos. Perhaps given the proper financial incentive things can be not so mediocre?
The coastal commission of California makes the normal Cali NIMBY suburbanites look like absolute amateurs.