It's not just scrollbars. It's the elimination of window borders. Aside from not being able to differentiate one window from another similarly colored window in the background, it's nearly impossible to click and hold on anything along the edge to resize the window. It's the overloading of the title bar with so much shit like search boxes and extraneous buttons that a user has almost no place to grip to move the wind…
I love not having window borders waste screen estate, and solve the grabbing issue by having the windows key + left mouse button bound to moving windows and windows key + right mouse button to resize. I can "grab" the window anywhere, with no need to hit borders or a title bar (which I also don't have...)
Now we have extremely high resolution monitors, and we use that to get really smooth angled lines and anti-aliasing, scaling up the visuals and decreasing the logical DPI, but the lack of a hard edge to grab doesn't get wider when the visuals are scaled up: it's still a single pixel wide.