Reading is one of my favorite ways to relax.
I loved teaching my kids to read, that process of decoding symbols in order to get meaning from them was so empowering.
Yes it opens a whole new world for children.
I think it also helps them with language acquistion if they are read to early, and of course discussing what you read helps them with learning how to share information and ideas.
Yes it's a great learning too. I think it also helps with their spelling.
But it certainly requires continual practice and development - even now that mine are teenagers and can read, I encourage them to always have a book they are reading.