Voyager was probably the most high concept of the era's Trek and didn't really fulfill that promise. It is funny that DS9 kept better track of its roundabouts over Voyager's shuttles.
They really didn't nail down the writing of the crew. The Doctor and Seven are the best written. However, out of the rest of the crew, only Tom Paris seems somewhat consistent.
You get some good episodes out of it, but I don't think it plays with the parts of Trek they were given to its fullest extent. I also feel like, while some of the shows are pure Trek, they aren't Voyager.
A big part of Voyager's problem was that the writers had absolutely no clue what to do with Kes. You had one of the main characters being just kind of there and largely useless. Once they brought Seven of Nine in and dropped Kes Voyager got a lot better. The writers had a clear understanding of how to write for Seven and she had a ton of character development over the final four seasons. Hell, I'd even say they did a better job with Neelix once they got rid of Kes, since they couldn't keep falling back on "Neelix is super jealous of Kes interacting with any male on the crew" BS they did a lot of. (And dear god was that annoying as hell. And I like Voyager!)
I feel like it wasn't just Kes who had this problem.
The Doctor and Seven were probably the best written characters. Tom and B'Lenna were probably the next two after that. Janeway only got better because she could act as a bad parent to Seven, which vastly improved her character and gave her focus. Neelix and Tuvok kind of drifted off to the background. Kim and Chakotay were blander than that, although Kim got a few decent character beats.
I'm not going to fault the actors on this, since this was the writing.
And Robert Beltran kept upping his salary demands each season hoping they'd fire him, since they were giving him so little acting to do. But they saying yes, so he stayed.