There are objective reasons why dark mode is worse than light mode, but I think anyone should be able to pick whatever mode they prefer.
See this for more info:
https://levelup.gitconnected.com/why-dark-mode-causes-more-a...
I have no data to back this up, but I suspect the main reason dark mode is so popular these days it's because there are a lot of users using devices in poor light conditions. The second big reason is probably more cultural, as dark mode looks more modern, unlike these damn boomer UIs from the 90s (sarcasm).
Some people argue about energy efficiency and OLED, which is true, but that seems like a niche use case to force dark mode on all your users.