Apparently there are studies where performing tasks was compared: in silence vs with music. Routine tasks were performed the same, but creative tasks suffered with music (i.e. a non-trivial solution to a problem was overlooked).

Dunno, however, if reading qualifies as such a task. Namely, the question is whether the same regions of the brain are engaged (and would be busy listening to music).

That’s incorrect, any kind of stimulus takes away some attention.

That's not true. Studies show that many pupils are better able to absorb information while doodling or by other repetitive actions. Many many famous authors have used long walks as a way to help themselves write.

The brain is very good at ignoring some sounds. Personally I'm fond of "white noise" generators - I have my own perfect combination of rain, wind, flowing water and nature noises that cancels everything else.

Maybe compared to silence, but often not net if it's displacing other stimulus.

I'm not entirely sure it's even always true compared to silence. Sometimes I feel like other bits of my own brain can be competing for attention and that occupying them can be a win.