Angry OP is angry, but yes, I agree this feature would be really helpful for enhancing the reading experience not just on mobile, but also in your normal desktop app. Being able to lock the zoom so that scrolling a page thereafter didn't so easily turn into a panning side to side re-centering exercise as well would really help keep the user's focus on the document they're reading instead of on reading, scrolling, and then having to recalibrate to the center at their current zoom level.
Angry OP is angry, but yes, I agree this feature would be really helpful for enhancing the reading experience not just on mobile, but also in your normal desktop app. Being able to lock the zoom so that scrolling a page thereafter didn't so easily turn into a panning side to side re-centering exercise as well would really help keep the user's focus on the document they're reading instead of on reading, scrolling, and then having to recalibrate to the center at their current zoom level.