I like some of my apps full-screen, like nvim in the iterm should be full-screen. The top bar, tab bar and controls is not something i wanna see all the time there, as i'm using only keyboard in my workflow. I'm mostly into zen black screen with 100 columns of text in the center when it comes to editing documents, and nvim + iterm can provide such flawless black zen screen. Also games, books, graphic apps, all look better taking 100% of the height not 80%, as the 20% on top is usually mouse controls for those who don't remember any hotkeys