Nothing about what I have been saying has anything to do with advantages or disadvantages of metal/non-metal armor. Nor about wanting something better than hide. Your response is a Strawman.
I'm talking about an exceptional circumstance, not wearing metal armor on a regular basis. An EXCEPTION does not alter the class story in the slightest, so does not need the DM's permission. Nor does it, per the Sage Advice, stop the druid from being a druid. It acts like a vegetarian making a necessary exception to the no meat taboo.