This is an ongoing thing, every forum is full of ppl wanting dark themes, yet each year and new software release features blindingly white, battery sucking themes! It's revolting!
I don't know any way except dark themes apps, and even then I'm not sure they actually do dark mode inside system menus..
The Queen of launchers, Ara Wagoner has encouraged us all to email google via the help link, and demand dark themes!
I'll be watching this thread with interest to see if anyone comes up with a workable solution.