It helps me a lot due to my situation & its also my personal preference.
But as for functionality, due to my job & other hobbies i get emailed a lot through out the day & have to reply back.
I also need to monitor certain applications for my work.
Having it in windowed mode i can just quickly minimize it so i can shift to my work.
Since i haven't heard too many people complain or ask about this i'm assuming either most people play in full-screen or just don't care that much about it.
I understand not implementing it for the few so you can focus on the majority but nonetheless since it never hurts to ask, i would be immensely grateful if this feature is implemented in the future.
Thanks again for taking your time to read my (& other) comments @
Aesouh