Is Dark mode a feature or fashion?

Half my users ask for it. The other half will never touch it and don't care.

It sounds like a small ask until you realize it doubles my design surface — every color, every chart, every illustration, every email template, every PDF export needs a second version, and they all need to be maintained forever.

It's the single most requested thing in my inbox, which makes it feel mandatory, like a table stakes feature I'm embarrassingly late on.

But it's also pure cost with no obvious revenue attached, and every hour on it is an hour not spent on the thing people actually pay for.

I've seen products launch dark mode and get a wave of goodwill. I've also seen them launch it, break their charts, and spend a month fixing it.

Do you build it because it's expected now, or hold out until it's a genuine dealbreaker? And has anyone ever actually left over it?