Obviously people want GUIs. That's why TUIs should be compared to GUIs, not to CLIs. TUIs are nice since you get a lot of the benefits of a GUI, without having to leave the context of the terminal.
I feel like the better solution here (than trying to shoehorn a GUI into an interface meant for text) is to make terminal windows graphically-aware, like how things work in Plan 9.
I already do use tiling window managers and they don't really accomplish the “if you launch a graphical app in a terminal window it takes over that terminal window” flow. Closest I've found is Niri's support for tabbed windows, but even that's just sticking the graphical app window on top of the terminal window instead of the terminal window itself becoming the app window.
Depends, I'm building a markdown down editor that just previews in the web ui. However, I can use the web ui to do tasks like uploading files, view git commits etc. Different interfaces for different purposes. The CLI gives me focused mode, and then visual stuff that steal my time goes in the web
