Why hard disc?

Firstly, apologies for my lack of knowledge on the subject and for posting some really basic questions. Basically, in many ways, I just don't get what all the fuss is about. Why is the ability to store music on a hard drive and replay it such a massive advantage over CD's? I feel that I must be missing something really fundamental here. I have been reading various posts on the forum in order to try to enlighten myself, but I'm still none the wiser. OK, so you won't need all those shelves of discs in your room any more. Or will you? What about cover artwork, sleeve notes etc. Is accessing a particular track from a hard disc machine really so much easier than putting on a CD? What about the amount of time needed to transfer all your CD's to hard disc? This would surely be prohibitive with all but the very smallest of collections. Surely it would be a full-time job for someone to undertake this, lasting many weeks with all the indexing required? This can't be right surely. What am I missing / not realising?

Thanks,

Peter