So I watched some STV and I see a lot of comments on spacebattles.com and other sites that Voyager totaly weakened the Borg a lot. Why do people assume this?
Voyager was prominent at the time and often went with the Borg in the last 2 seasons. But the real culprit is Star Trek First Contact.
Introduced the Borg Queen:
This was a contradiction to what TNG told us about the Borg. That they were a collective. First Contact reversed all that by making it a hive mind. TNG reinforced the collective mind with Troi's empathic perceptions and they further said there were NO individuals. This means that the borg were all conscious individuals working in concert to a common goal. Locutus merely became a figure to represent the Borg to the Human race...a mouth piece.
Introduced Nanite Assimilation
This didn't fit with the Borg of TNG.
Hugh never tried to assimilate any of his captors
Neither did Lore's Borg attempt this sort of assimilation
First Contact portrayed the Borg as zombies, physically. missing body parts. Instead of Pale white they had a translucent veiny apparence, Instead of clean surgical prosthetic their limbs seemed disfigured and incompetently modified. Along with this zombie effect there was critical color added to all borg functions....green...tractor beams, lights of any kind and weapons were suddenly and inexplicably all green.
Lost of Regenerative Abilities.
Borg ships previously had the ability to regenerate at incredible speeds, this is what made defeating the Borg so difficult at wolf 359. No ship ever regenerated in such a way ever again.
All in all First Contact is the origin of the stupid Borg. Voyager just followed suit. So the claim that Voyager is to blame is bit nonsensical. Rick Berman is to blame.