Are you sure about that? Maybe relative to the total usage of the line yes, but the option for rapid crosstown lines especially when they connect to a ton of nodes of interest (like Eglinton West) is extremely important. Plus even if people aren't travelling end to end, having a section that isn't grade separated and can get stuck behind red lights negatively impacts the rest of the line. We see this with Line 1 where a delay at York University can cause problems for someone riding between Lawrence and Wellesley, only here your source of disruptions are so much bigger and so much impactful.