Godot is tiny and starts up fast but it also starts up with a console that I personally find unnecessary.
It has its purpose but usually it's just another window that ruins my alt-tabbing speed! Fortunately it can be hidden. Under Editor > Editor Settings, you can search for the Hide Console Window option and flip it on.
This value is persisted so the next time you run Godot, the console window will hide automatically on startup. For me, it's stored in AppData/Roaming/Godot in a file called editor_settings-3.tres.
[resource] interface/editor/hide_console_window = true