Come on, I lived on the Isle of Dogs (2 manilla st) for 2 years. That's right next to Canary Wharf (a literal 2 minute walk). While it's true the actual Canary Wharf area has its own private guards its not a typical gated community. Yes, there are clever underground car barriers(I don't think I ever saw them closed though), but there are no surrounding fences etc. I don't think it's a good example of a "private owned gated community" at all. Anyone can just walk in.
Also, Isle of Dogs is a great example of how private/public partnerships can lift an area out of poverty. The Tower Hamlets area which Isle of Dogs is a part of has been a very poor area with lots of drug/theft/poor housing problems etc. Then lots of high rises were built (including the one I lived in) and some petty crime remained, but the quality of life was pretty good there. The best things being really good access to public transport, access to the river, shops/restaurants an NHS health centre that isn't overwhelmed with patients etc.