Device Preview missing from the Window panel

This is disheartening, I came here to find out where this functionality went myself. I believe I was just using it a month or two ago before the last upgrade.  While I didn't bother checking what my designs looked like on Android, I did check them on an iPhone to see how they would look on a mobile device. I only do 3-4 web applications a year but I used it every time I did design work. Even only supporting iPhone, is better than nothing, you can still get a sense of what something will look like on an actual mobile device in terms of scale and proportions. Thankfully I use a mac so there are other options for me, like Sketch. I will be very honest with you, the only reason I had gone back to Photoshop from Sketch was because they added that feature. I'm not here to bash Adobe or it's products but that was a very important feature to my workflow and my validation process. Maybe not many people used it because not many people knew it existed, there is an awful lot of functionality in photoshop that not everyone uses. Plus Adobe's plan was to make Photoshop more of a web / app based design tool and they had added a lot of features that Sketch had, like art boards. Before you only had Art Boards in illustrator. So by trying to turn Photoshop into a Swiss Army Knife like design tool, of course you're going to wind up with some features that aren't widely used however I bet more people used it than the fish eye lens filter that has existed in Photoshop for like 30 years.