Why are ther 2 speaker on all iphones?

hello

i'm an iphone user sonce the iphone 3 and there is always 1 single thing that I do not understand.

every iphone has 2 speaker. One for calling and the other for the rest.

why can't we just use the speaker for calling for everything? You will get a sound inprovement and because most cases alread got a cut out part for this speaker it will not hurt it in that way.

this will also fix the problem with your hand while watching videos that you don't excedendly cover the second apeaker with your hand.

THe only reason that maybe exist is that speaket needs room to sound great when its louds

so what are your thought