I appreciate that the plastic bag rule had some logical basis to begin with but surely by now should be revised and applied with common sense. I'm sure most security staff are capable of using some intelligence.
My experience - young daughter had nothing but a small tub of favourite lip balm in a transparent outer pocket of her bag. "Sorry, not allowed as no plastic bag" Kind lady behind says "give it to me", puts it in her plastic bag, goes through security and hands it back. Security and little girl happy 😊