Is the idea to switch automatically during local nighttime? What is the intended way to switch themes?
I am surprised this is apparently important to 83% of people - I never missed such a feature myself.
I just use Redshift to change brightness and color balance at night.
I like my websites to always look the same. And black text on white background has been proven to be more readable, so preferably that all the time (also because I am awake longer during the daytime).
I also don't use dark themes for IDEs, since light themes were proven more readable. I always figured people just use dark themes because they look cool, but maybe I'm wrong.