Re: Did the alien design on Voyager just get lazy?
I don't think some storylines require or are worth the time and effort of creating radically different and unique aliens.
A lot of the time a generic 'forehead of the week' design will suffice.
Inevitably when faced with seven years' worth of creating new designs for alien races some will be more radical than others - for every Species 8472, Hirogen or Vidiian you'll get half a dozen Taresians or Krenim-type aliens.
I wouldn't call it laziness as much as the reality of weekly television production.
It was more than 7 years by the time the later season of VOY
7 years of TNG
Almost 7 Years of DSN
Plus several years of VOY
On the continent of wild endeavour in the mountains of solace and solitude there stood the citadel of the time lords, the oldest and most mighty race in the universe looking down on the galaxies below sworn never to interfere only to watch.