Not the author, but I’ve been coding since the 90s and also ended up switching between light and dark depending on the time of day. The trick is to also adjust screen brightness. With light background you can lower overall brightness. With dark background if you’re in a well lit room, you have to increase brightness to the point where bright words on the screen actually shine too strongly in relation to the dark background. So it actually feels gentler when the background is light but screen brightness is dimmer overall.
Over 10 years. I used to be dark mode all the time, but in recent years I feel light mode in daytime is much clearer and doesn't clash with the ambient light which forces my eyes to strain more in daylight.