abirdcall
(she/her)
Just quoting you as one of the many, but note I don't have anything against you specifically.
What do you do if a Druid player in your campaign, at some random point during an adventure, finds and dons a metal armor?
a) Do you punish your player's PC "mechanically", coming up with some penalty that isn't in the rules?
b) Do you punish them "socially", altering the story to make it harder for them?
c) Do you flat-out tell them "you are NOT doing that, because I tell you so"?
At my table that wouldn't happen because we follow the rules.
If a player didn't know I'd show them in the book and then we'd move on.