Frankly I think saying the loss of a single character from a series devalues any fiction that's a part of that series actually unfairly devalues the other characters from that series more than anything else.
In other words - if you feel that a Trek story requires the captain from the series that story is tied to, IMO you're doing the other characters from that series a disservice.
Any storyline is nothing more than the summation of the main character's trials with the supporting characters adding flare for dramatic effect.
Star Trek's main characters have always been the Captain of the ship with two other characters that were high up on screen time followed by an assembled cast of supporting characters.
Hack it any way you'd like, the truth is that the Captains of Trek are the main characters.
That doesn't devalue anything.
The Farseer Trilogy wouldn't be that if Fitz wasn't in it. That story ends and another begins if Fitz is removed. It's a new story set in a familiar world setting.
Gone with the Wind isn't GWTW if Scarlett isn't in the storyline. It's a new story with some familiar faces.
It's not that the books are not
Trek stories, it's that they are no longer really
Voyager stories because the main character is
gone.
There's a reason why the Trek show in the 80's was called Star Trek: The Next Generation and not Star Trek. It had some familiar faces, but it wasn't the same show. To say otherwise would have been disingenuous.
This is not true of how all genres work, but it is, IMHO, how Trek as a genre works. It's still the same universe, but it's not the same series once the Captain is gone.
In DS9, Sisko was pulled out of the universe on screen with a great deal of storyline to back it all up. It was bittersweet, but the fans of that series saw it coming (some did anyway). I see this is an apple to oranges comparison at best.
You are welcome to, of course, continue to come in here and say that those of us who are irritated that the captain of our favorites series has been killed off aren't being very true to the series, but Voyager was fairly unique in that Janeway's push to get home and her character(personality) that pulled her crew into a family was a hard driving force in our series.
Completely pulling away a binding force such as that
does make the story less to many of us.