It’s very true on a Mac. Almost every time you click the green button, it jumps to full screen and then you can’t drag another window on top of it.
It’s a pain in the arse because my workflow is to have a reading screen with documents and emails on, and a work screen with whatever I’m actually doing. But if outlook is full screen, you can’t drag any other windows on top of it.
Don’t know why the first guy was saying this is a Windows thing though. I only run onto it on macs.