Simplicity should be to self-service as chocolate is to joy or sadness is to taxes. Human-to-human service (the "opposite" of self-service) is rich in flexibility, cues and empathy (unless you’re dealing with an ignorant service professional). Human interaction oils the path towards successful task completion. A self-service design must be very simple because it doesn’t have that human oil.
Imagine you’re a manager of a restaurant. You’re standing near the front door and you see an old lady approach. If you’re any good at your job you will open the door with a smile. However, that same old lady could be squinting at the tiny, grey text on your website and you will in all likelihood not even be aware she exists.
It’s hard to say to a webpage: “I don’t understand you.” It’s hard to say to an app: “Are you sure this is the right direction?” (I mean, you can say what you want to a webpage, scream at it if you want, but it’s not likely to respond.) A friendly Human Resources manager may say to you: "Don’t worry about reading that section. It’s not relevant for you. And this section here, this is what it actually means.” They are bringing years of experience to bear on the human-to-human interaction in which they are engaged.
A good doctor can make a serious and complex situation reasonably simple and more comforting for a patient. They can bring empathy and understanding, thereby reducing stress and confusion. They can adapt to the specific demands of the here and now.
When you go into a self-service restaurant you don’t want to search for the menu. When you go into an expensive restaurant, you often have to wait for your waiter to give you the menu and pronounce for you the complicated French-sounding words and explain them, while you nod and give the impression that you understood the menu from the get-go. It’s a little bit of a ritual, adding to the atmosphere and your education. (That must be nice because it’s simply unpronounceable.)
Self-service is a different beast entirely. The stomach is rumbling and the pocket doesn’t have much cash. Once you find a self-service menu you tend to scan it quickly. If it has too many choices or the words aren’t simple, chances are you’ll get annoyed and either say “give me a Big Mac meal, please” or leave.
A huge amount of stuff that ends up on the web has been created either deliberately or implicitly for human-to-human service. The human resources policies really do need a human resources expert to take you through them. The installation guide will make perfect sense once you have the engineer who designed the system sitting beside you. The description of the course truly comes to life when you have the professor responsible for it on the other end of the phone.
The reason why so much "print" content is migrated to the web is because it’s cheap and easy to do. Organizations are making life easy for themselves and miserable for their customers. However, they will pay the price in reduced customer loyalty.