Eh, I don't agree at all. Maybe that's the case if you don't use adaptive brightness and your whites are max intensity. I prefer a dark theme I can use all day and let the brightness setting modulate the contrast. That way, direct sunlight kicks in the high contrast capability to make the theme usable during the day (which destroys these gray "dark" themes), while dropping the overall contrast ratio to something similar to these gray themes and emitting less light overall at night.

Pure black doesn't feel like I'm looking at a box light and makes transitions between text and media much more consistent. I end up futzing with the brightness for mixed media (like embedded videos or images) far more when using a gray dark theme, since the true brightness will be much more intense for "media white" than "text white", and the perceived brightness between them will be even higher than that.

Dark themes used to be about practicality and health. Current gray dark themes seem to be born from poor contrast ratio LCD limitations and justification for the aesthetics around the old Holo theme. As someone that has religiously converted their most common sites to dark themes with custom CSS (a few hundred as of now), gray on gray themes feel foggy and I only use light-but-still-dark gray backgrounds on sites that change frequently so I can see if there's a new text element that needs to be styled.

(But, I'm probably in the minority. I also drop font sizes to reasonable levels, delete rounded corners on elements, and remove the miles of whitespace from sites unwilling to accept that a two paragraph "story" isn't worthy of the engagement metrics they get by wasting the reader's time scrolling.)

Not to mention OLEDs don’t turn completely off and on very quickly so you get a lot of smearing on full black screens. Gives me a headache.

grey text on black background looks decent. Does this hold up for a true black background?

In the post you replied to I stated two specific benefits of dark mode. I don't understand how you got from that post to "gimmick."

- Dark mode saves battery (for OLED displays). The discussion was on "true dark" Vs. grey. Not dark Vs. non-dark modes.

- Dark mode is useful in low light/dark rooms/night usage.

It isn't a gimmick and a lot of people like it. I happen to be one of them. I'd use it even without any battery savings.

No way, dark mode is great. Combine it with an internet browser that has a night mode (Samsung's fork of Chrome) and the phones are significantly more pleasant to use at night.

I love dark mode because it hides my eye floaters

I dislike "dark modes" and don't use them at all, but I can see that they are of real value to a lot of people and not just a gimmick.