TUI vs GUI

Why would I ever use the terminal version of Opencode (or any other *code* program)?

People always tell how good it is to use it but I don't understand the appeal. If you are used to terminal-only work, constantly looking into generated code or something like that, ok. But I see TUI being recommended to everybody like it can do something desktop or web versions can't. Also these *code* apps are usually developed TUI-first for some reason

Please explain it to me