Designing for mobile - Undesigning for desktops

Designing for small mobile devices and tablets has taken over with a vengance. I'm confronted with sites where the top third or more of my desktop screen is taken up by a (often meaningless) image. I was just looking at a post on medium.com where my entire monitor is taken up by an image. I have scroll to see any text at all. And...the text runs down the middle of the screen. Navigation is... where? I had to enter a new gmail contact today and you can see that I might be better off completing the transaction on a small device using touch. I gather the idea is "progressive enhancement": design for mobile first with enhancements for large monitors. I think designers are leaving out the enhancements. I know I'll get used to it after a while, but right now I'm finding it really annoying.