It’s a classic, if somewhat exaggerated trope in Star Trek: The ships first officer, second officer, tactical officer, chief engineer, chief medical officer, and a random ensign beam down to an unsecured planet while some dangerous problem is either ongoing or likely to occur. The Doylist reasons for this are as obvious as the Watsonian reasons it seems so silly: these are the main characters who are supposed to get the bulk of the screen time, so they are constantly thrown into situations which real world commanding officers and department heads are generally kept well clear of.
But what if this wasn’t the precedent established in TOS and continued in every subsequent series (including, to a slightly lesser but very real extent, Lower Decks)? What would a Star Trek show look like which still had senior officers who we are meant to care about and who still get significant development and screen time, but who aren’t thrown into unrealistically dangerous situations on a regular basis? Could such a show survive telling stories without visibly putting those regulars lives on the line so frequently? Would it be viable to keep the focus on things that happen either aboard ship or in nominally safe situations? Alternately, could a show successfully develop a cast of lower ranking “away team” characters who get the “dangerous” screen time while keeping significant focus on the major decision makers on the bridge? And how could the shows manage such a visible separation between “expendable” and “not expendable” crew while maintaining that humanist, optimistic, everybody-has-an-equal-right-to-life ethos?
It wouldn’t be an easy thing to pull off, certainly. But how could it have been done?
That’s actually an excellent point with early Discovery, a connection which had not occured to me despite working on this morning’s post. Discovery absolutely does try to do this, and for the most part it works; it only really falls apart when the show shifts to extremely grandiose storylines and feels the need to put Burnham in the middle of all of them. The early goings, essentially a war story told from the perspective of some science specialists who really ought to be the ones in the middle of those situations, makes considerable sense.
That post is actually what made me consider how well Discovery managed to do what the OP mentions in their first season. Answering the question of “why send all the senior staff” by making the main players not senior staff just works.