You just have the item in red/gray (requires X). And I think it is fine if you have 1. Research Lab (requires university) 2. University (requires library) 3. Library (requires campus) at the top of the queue. As soon as I build my campus it goes 1..can't do 2..can't do 3... I can do this one so start on it (once 3 is done, it still can't do #1, but it can do #2 so it starts on that) And If I look at my queue and wonder why isn't X getting built... I can see 1. Research Lab (requires university) 2. Library (requires campus) Oh, I need to place a campus... and add a university to my queue somewhere. Very nice.... however, while a queue is a very important thing to have, civ6 has Much bigger problems, and if they prioritized putting a queue in, some other part of the game would probably be even worse, because they didn't fix that.