And what good are any of those if the city, one by one, loses everything that makes it a place worth living in the first place? This is the problem with the whole post-WWII, neoliberal brand of "progress". Just because it's desirable for us to move forward as a society doesn't mean we need to steamroll everything pleasant that we come across in our travels. We aren't talking about building on some random meadow here; the Toronto Islands are fairly unique geographical location, they are a beloved getaway spot right in the city, they are a significant recreational and tourist area, and an important part of the overall fabric of the city. How is it desirable for this to be at least jeopardized, if not entirely eliminated, so that we can expand an airport?
Is it a problem for Paris to have the Notre Dame instead of an airport in their core? Does Vienna struggle by having the Stephansdom instead of an airport in the city centre? What about Budapest with their Országház, or the Prague Castle? Should Central Park also be paved over and an airport be built there, too?
The very notion of having an airport right next to downtown could only have come about because the city planners of yesteryear had no sense for the aesthetic, and allowed industrial development along the entirety of our coastline. Now that the coastline has been converted into a vibrant mixed use district, it is beyond inappropriate, and the idea of expanding it at the expense of more green space is sick. If it makes me a NIMBY to not blindly promote progress at the expense of all other things that bring flavour and pleasure to life, so be it. I'll even get a NIMBY tattoo. Let's not degrade a fantastic place to exist so that we can make a bunch of businessmen happy.