Well the Borg appear to learn by adapting/assimilating knowledge. So you have the UFP which has shown an ability to come with new tech to defeat you on several occasions. It could be argued from a long term view that sending a cube once every few years to try and assimilate is a good idea. At worst you'll learn about a new tech and best you will be succesful.
As for the question at hand did VOY weaken the Borg, The more a villian is used the less threatening they becomes. Where VOY I think runs into problems is that the Borg are considered to be more advanced that the Federation. And in the major borg encounters from TNG how they where handled varied
"Q Who?" Q snapped his fingers and saved the Enterprise.
"Best of Both Worlds", The crew managed to access in essence the Borg and order the ship to regenerate. After the Borg had blown had destroyed 39 out of 40 ships at Wolf 359
ST:FC, The Borg ship has taken a fair amount of damage and destroyed numerous ships, but thanks to a residual link Picard is able to determine a weak spot
As for "I, Borg" and "Descent" they didn't deal with the collective.
So simply put VOY over used the Borg, in another Sci-Fi franchise DW the same argument is sometimes used in regards to the Daleks, there is however one slight difference the Daleks are at best equal in terms of tech level to the Timelords. So when the Doctor defeats them he is from a race that is more advanced than the Daleks at best and at worst equal.
As for the question at hand did VOY weaken the Borg, The more a villian is used the less threatening they becomes. Where VOY I think runs into problems is that the Borg are considered to be more advanced that the Federation. And in the major borg encounters from TNG how they where handled varied
"Q Who?" Q snapped his fingers and saved the Enterprise.
"Best of Both Worlds", The crew managed to access in essence the Borg and order the ship to regenerate. After the Borg had blown had destroyed 39 out of 40 ships at Wolf 359
ST:FC, The Borg ship has taken a fair amount of damage and destroyed numerous ships, but thanks to a residual link Picard is able to determine a weak spot
As for "I, Borg" and "Descent" they didn't deal with the collective.
So simply put VOY over used the Borg, in another Sci-Fi franchise DW the same argument is sometimes used in regards to the Daleks, there is however one slight difference the Daleks are at best equal in terms of tech level to the Timelords. So when the Doctor defeats them he is from a race that is more advanced than the Daleks at best and at worst equal.