Search is an UI element for most people
Search is bloody awful as a primary method of interfacing with a computer. Gnome Shell, the god-awful Unity and Windows feels otherwise. For me, a power user it's fine, it's actually how I tend to run apps. In windows Win+R then the app name, in KDE (my regular desktop) Krunner does the same. FOR ME, a touch typist, it's quick and simple.
For my 78 year old mum, it's bloody awful "you mean I can't use the mouse?" she says.
"well you can, but it will take forever" I reply.
But as she isn't a touch typist, isn't even familiar with a keyboard layout, taking her away from a menu and mouse icon is painfully slow (and painful for her hands at times too)
Moreover, Search is only useful if you KNOW in advance what you're looking for. I know that my web browser is Firefox, Opera, Chrome, etc and my email is Evolution, Thunderbird or Kmail. for "normal" people they don't give a monkey's toss about the name of their application to a lot of users they have "The Internet" and Word. and that is pretty much all they ever use or care about.
Search is great for power users, great for touch typists or fast "hunt n peck" but it should be the alternative, the secondary way, the way you interface when you grow skilled or when you're totally lost, in that case, you need to search to be clever, and in my experience it's only clever if you know the right geek speek.
We've spent the last 30 years getting used to interfacing with a mouse or a mouse style pointer (touch being a fairly natural extension of that method) Now with this move towards typing Microsoft is forcing people away from usability and demanding they learn how to type in order to interact with your pc.
Search is probably great for me, great for you too, as you're geek enough to be reading this, but for normal everyday "real" people (with lives outside of the computer) it's a bloody idiotic methodology.