I was thinking about the phrase ‘The pot calling the kettle black’. It comes from a time where cooking was done over open fires and cookware would become visibly ashy. (Fun fact: It first appears and was perhaps coined by Cervantes in Don Quixote!)
What are some other idioms that have lost their literal connection to time? What would be a good modern replacement?
I think the outdated/obsolete nature of terms in many idioms is what makes them charming.
It also makes it pretty clear you aren’t using them in a literal sense. If your idioms are too new/unfamiliar and your terminology is too modern/relevant then people might just think you’re being literal and not idiomatic.