It depends - if it is done for story driven dramatic purposes there will be a point. There will be a plot with structure that utilises it.
It can also be done more in a 'reflecting real life' way, unexpected, senseless, pointless and with no structured story point. Which is not to say that there will not be story opportunities and developments spun off from it.
Exactly. The problem with demanding that there be a "point" to every character's death is that death is frequently pointless and random. It's hypocritical and dishonest for a story to kill off faceless redshirts casually while never letting the audience lose anyone they care about unless there's some "meaning" to make them feel better about it. Every one of those redshirts was a very important person in somebody's story, important to their families and friends and loved ones.
That's why I admired what TNG did with Tasha Yar's death. She was killed off just as randomly as any redshirt, but for once they approached it honestly, let us feel
the painful consequences -- the doctor's fierce, futile struggle to save her (infinitely better and truer to life than a two-second sensor wave and "He's dead, Jim"), the grieving of her crewmates, the struggle to move on with their duties despite the loss, their bitterness toward her killer, the tearful and cathartic memorial. Presumably the same thing happens offscreen when any redshirt dies, but for once ST was honest enough to let us live through it rather than sweeping it under the rug and having the bridge crew joking and laughing twenty-five minutes later. That's
the meaning. That's the point. That no death is unimportant, that every life matters and every loss affects people whether there's some important plot purpose served or not.
(Which is why I deeply hate it that "Yesterday's Enterprise" denigrated Tasha's death as "pointless" and replaced it with a more cliched, juvenile fantasy of a "heroic" death. It's an insult to every rescue worker or firefighter or police officer who dies in the attempt to save lives. It's never meaningless or pointless to give one's life trying to help others, even if you fail to do so. Armus's act of killing Tasha had no meaning, but Tasha's choice to put her life at risk for others was a profoundly meaningful thing.)