the Borg's ability to adapt at such an incredible pace to both technology and battle methods is an incredible advantage.
Also, their ships are much bigger and more advanced.
The Borg should win hands down, but the Borg have been written well below their actual abilities since they were first introduced. It's an example of introducing an adversary that's too powerful, so they get taken down more and more over subsequent appearances.
Not "an" example. THE
example. They're the epitome of the problem with introducing an adversary that's too
Imagine what Star Trek would have been like if the Q were written as an aggressive enemy!