I'd really rather just zoom. There's no real mode switch for me any more. To me, zoom is just a UI option that's a part of the mobile browser experience. Also, sometimes reader mode doesn't work, since it depends on one of a few technical tricks. Zooming is just basic geometry. If Apple wanted to, it could always be active, and it would always work.

I said it was just a tip, not the ideal fix. For someone it could be an acceptable solution.