Not exactly that I think going through with the ending was impossible based on the premise, and more that I lack faith that they could have pulled it off properly. It sounds simple; get back home, but I'd not be surprised at all if eight seasons into the show there was an insane religious arc where Seven of Nine was having visions of a red angel and two seasons of the show took place 200 years in the future.
Wait, that wasn't the finale? (lol f Endgame)
Yeah, I know it wouldn't be precisely that bad, but there's no shortage of ways where the plot could have spiraled off the rails if they started trying to market the show as more serious and edgy. There's not even a straightforward way for them to actually get home that the show could build towards, so anything they could come up with would be about as bullshit as the actual ending we got. I just see it falling victim to the same mystery box bullshit that we've seen with most modern TV shows. Its not a new problem; the X-Files also suffered from it.
It was either on here or the Star Wars thread but as I have tried to explain repeatedly: Serious != edgy or humorless. Even comedies - well done ones - take the story and the delivery of jokes
seriously in their execution. For a comparison, Lower Decks vs GalaxyQuest. DS9 was even more serious than TNG but they still had time for great comedy moments and episodes. The principle is that they always took the characters, setting, etc
seriously - as like real things and people.
Voyager having the magic reset button every episode proved the series was unserious as assuredly as it would have making Neelix the captain. Remember the episode where Ensign Kim slept with an alien and LITERALLY got an STD that lit him up like a christmas tree? Fair Haven? You really want to defend some of this stuff?
Conversely, having the show take its premise serious doesn't mean you exclude comedy. You could have an episode end with Voyager limping away from a conflict, and then follow it up with the next episode being Janeway inflicting Tuvok and Neelix as a double act upon the space equivalent of a used-car-salesman to get the parts they need for repair. A comedy episode, that works
as comedy because the plot is taking the premise and set up
seriously.
Voyager had a fresh, original set up with opened up the possibility of stories that Star Trek had never explored before as well as an opportunity to explore new possibilities in storytelling. It also had a decently talented cast that could pull off great scenes. The behind the scenes crew were also experienced by now and technology advanced to the point they could pull off special effects for their stories at a fair price.
All that, and even at its best the show can barely get above mediocre most of the time.
(And XFiles was NEVER planned to have any kind of myth arc or ongoing storyline. That was its problem.)