Two reasons I personally use Evernote for:
Documentation on the go - support on any device, with multiple input formats (handwriting, audio, attachments, pictures, contacts, third party integrations etc). Note to self: never go to any meeting with a laptop, instead, take notes by hand and later scan them to Evernote.
Search - All my notes are scanned and indexed, so I can search any piece of text or other information I tagged accordingly. Location-based search is also handy.