Why don’t we see film grain in theaters?

[diamondfoxxx]

I’d really appreciate it if somebody could educate me on this.
So the logic I hear for the presence of film grain in BD’s is that their resolution is higher, which gives us more detail and in turn we can also see the fine grain which is inherent in film. But the resolution of film is higher than a BD, so why can’t we see the grain in theaters? Is it because of the screen size? If so, if I blow up my BD to a 110inch screen will the grain be unnoticeable? Or is it because of the analogue method in theaters and the digital method in home use?