I wouldn't have wanted another 16 seasons of Voyager either. So yeah, I get why the writers sent future Janeway back to year 7. From an in-universe standpoint it just doesn't make a lot of sense though. The writers could have rewritten this episode in a way that would have avoided that confusion.
Yeah, here's a suggestion: Have them get back to Earth at the end of season 7 via conventional means, and not through the benefit of time travel.
The very act of showing us an alternate future and implying the existence of 16 years worth of stories that we never get the opportunity to see is a cheat.
They want to feature the Borg in the series finale. Fine. Rework the story so they fight the Borg and blow up the transwarp hub and fly back to the Alpha Quadrant WITHOUT the use of future Janeway and future-tech, and I'd be much happier.