The whole root of "the Loop" problem is that the Mississauga City Centre is located in the wrong place. A city centre normally evolves naturally over decades. It marks the place where it is most convenient for most people to meet and do business. I think in Mississauga that location is Cooksville, where the old city hall used to be. Cooksville has Hurontario Street and Dundas Street, and the GO line. It's the place where people will gravitate to most easily. Trying to force people to use a "city centre" located off a secondary arterial road, almost a kilometer from the main arterial road, behind a shopping mall, with no access to inter-city transit, is not the place people naturally want to be. The politicians have been fighting an uphill battle for decades trying to make a city centre in a place that is not a natural city centre location.
At some point they'll have to decide whether to keep throwing money at the problem, or just give up and let the city centre gravitate back to Hurontario Street.