It depends on your content. Dark mode can enhance usability if your content is color critical. If your content is rich in graphs and numbers, then dark mode does enhance the data. Here's a good article with an image to show how Dark UX can enhance statistics (green increases and red decreases are much more obvious):
https://observer.com/2019/03/dark-mode-app-trend-psychological-effects

If you have a blog that simply feeds articles to read, then dark mode is not a better design, it may even contribute to eye strain. Here's a good read in which Susanne Mayr, a researcher at the University of Passau who focuses on human-computer interaction, resulted in several tests that
“In all of our studies, participants were better performing in the
positive polarity condition,” says Mayr. “They detected more errors
and/or read faster when dark text was presented on a light background
than under reversed conditions.”
https://www.wired.com/story/do-you-need-dark-mode/
Great question though. Imagine a few years from now and see if Dark Mode is still a trend? If you appreciate my answer, how about marking it as an Answer ;)
– jhurley Nov 19 '19 at 14:45