I use light mode when I am working outside (which is a lot now that I work from home) or when I am at the office as it's got bright lights. At night or when I am in a darker environment in general, dark mode is great. Being able to quickly adjust the screen brightness also helps immensely (more so than the actual mode, actually... if I had to choose a single mode, it would be light mode, as dark mode is totally un-usable in a very light room/outside).