You *could* pull that illustration of a laptop and papers off with an SVG image, but you would still need to create the image in a program like Illustrator then export it as an SVG. There's no feasible way to hand code that image, it looks like a bunch of encrypted mumbo jumbo when you export the underlying code of an SVG graphic unless you're doing super basic stuff like a circle or a square.
You can build very complex and visually appealing user interfaces with just HTML and CSS. CSS can do a lot of effects these days, including complex gradients, glows, shadows, etc... Where you would still need actual images would be for things such as textures, or photographs of the subject matter (of course).