Chicago metro is still much larger.
We discussed this a few pages ago. Larger, but not still much larger. Chicagoland is 28,120 km² with 9.7 million people in 2010 (9.3 million in 2000). Greater Golden Horseshore is similar but a bit less area with 21,464 km². with 8.8 million people in 2011 (8.1 million in 2006).
And Toronto is growing significantly faster. Using a very simplistic straight-line approach using just that data, Chicagoland is growing by 40,000 a year while the Greater Golden Horseshoe is growing by 140,000 a year. If those rates hold, Greater Golden Horeseshoe overtakes Chicagoland in 2021 and 1 million more people in 2031.
And our transit infrastructure definitely lags by about 20 years.
Most of Chicago's rapid transit infrastructure has been there for decades. We don't have their "advantage" of significant depopulation of the city proper.
The current boundaries of the city of Chicago had a population of 2.7 million in 2010, but 3.6 million in 1950, and about 2.7 million in 1920.
The current boundaries of the city of Toronto had a population of 2.6 million in 2011, but 1.2 million in 1951, and about 0.6 million in 1921.
I'm sure we had the same advantage of having the same population today, as we had 90 years ago, then our transit infrastructure wouldn't have lagged by 20 years!
It is because it shows Toronto is growing. That's all.
That would be it in a nutshell!