Basics of Halftone Screening 

Of course For printing, You can't just produce every pixel on the paper. By halftone, we are creating an illusion to our brain with dots which in turn believes it to be an image rather than a group of dots.

@@VinayakR1 also imo halftones have a texture very uniqe to it and that has a big appeal

Halftone's main purpose is printing, analog printing: screen printing, offset, flexographic, press