I’ll start by saying I loved the musical episode. Don’t think it would, but I was very wrong. Watching season 4 now, and I have to wonder, are they just making the show all gimmick episodes now? Each episode isn’t bad on its own, but I really wish they would get back to telling Star Trek stories.
They are telling Star Trek stories. This season, the stories are about the crew. Each one of them went through traumatic experiences, and this season is about the crew working through their trauma and coming out stronger on the other side. Plus, the way they provide in-universe explanations for each episode’s format is simply brilliant. You call it gimmicky, I call it art.
This season really has had some great characterisation. Kirk’s family issues, Scotty bonding with Ortegas in one episode and the Enterprise in another, and Pike’s coming to terms with the loss of his pocket universe family were some of the best moments those characters have had in the series.