Willie the Duck
Legend
I generally assume it is cost of people and/or space when such things happen.Question -- how many cadets are there at the Academy? It seems like there's about a dozen? Not enough to fill one department on one starship, let alone a fleet. I assume there was some sort of training program in place beforehand, otherwise who would be crewing all the current Starfleet ships? Was that the War College?
Then again, maybe it's the Strange New Worlds extras cost problem which made it seem like there were only about 10 people on the Enterprise. Maybe there are hundreds of cadets, but we only see a dozen of them?
Schools and sporting events and parades are a problem, in that you want a whole bunch of extras just doing/being in the background. If you can have individual classes and only see a brief hallway scene of massively multiple classrooms worth of people moving about (one shot for a whole season, or maybe you can green-screen and layer the same people in different outfits or the like), that helps a lot. Star Wars stumbled upon a great shortcut when they had stormtroopers standing in formation be something you could paint onto a scene and then just include the moving ones as real people. Star Trek always was better with locations than people, in that they could afford a matt painting of Planet XYZ or building ABC, but not 200 extras, a place to shoot them in, and a choreography team to make it look natural.

