I completely disagree. I personally find dark mode harmful to my eyes. Try this: open a page full of white text on black background. Stare at it for 10 seconds. Now close your eyes. You can clearly see the afterimages of those bright text lingering for quite a while. Now try this with black on white page. No afterimage at all.

Like the author says, if the screen is too bright for you, lower the brightness, or use night light mode. You can change your environment. You can't change how your eyes/brain function.