Among the musical skills that can be acquired, "sight reading" is somewhat specialized, but definitely real. I'm a part time musician, and a fair amount of my performance work over the past decades has involved sight-reading. In addition to its usefulness for performance, it's an efficient way to digest a lengthy or complex work.
It really depends. If you want to make music you don't need to be able to sight-read, but if you want to be a functioning member of a Jazz/Events (i.e. you play what they want) band you need to be good at sight-reading.
