I'm not sure why they don't provide a DM screen with sleeves and a number of sheets as every DM prioritizes different information. And you could also open a market on DMs Guild for campaign specific supplements, maps etc.
Still so much wasted space... why do I need a visual chart showing monster sizes taking up half a page? Why do I need info on beer and lodging prices when 5e seems to intend you use its "lifestyle" method for tracking expenses? Why is there player information (Things you can do on your turn) on the GM screen? Shouldn't that be on a character sheet?
I'd even question who needs to be reminded of how to set DC targets. That's the kind of thing that even the newbiest of DM is going to have memorized within a few sessions.