The screenshot was taken from a live stream at 1:30pm on a Wednesday, not during long-weekend rush hour.
The Gardiner, just like the 401 and the DVP, are a traffic nightmare nearly all the time, yet they don't have bike lanes on them.
This isn't some strange coincidence or conspiracy.
Car dependency, rather than people riding bikes, taking public transit, or walking, is the real problem causing traffic and gridlock.
Traffic is worsened by people driving cars badly, but traffic is caused simply by people driving cars. Cars are highly space inefficient, especially when on average they're moving ~1.4 people.