There are good prime directive episodes, but on a whole they just aren’t good intros to the shows.
For example, Pen Pals from TNG has some great moments. The crew indulging Data, everyone knowing Data has an emotional connection with the little alien girl, except Data. Good discussion about the morality of intervention. And a large chunk is Wes being whiny also pretty goofy make up on alien girls hands. It’s good, but not an intro to Trek good.