I see them as farmers.
They wait out other civilizations for new innovations.
There's no point in assimilating redundant technology.
That's the opposite of lazy.
The restraint it takes not to take raw resources and man power on the off chance that the planets they're watching might create something interesting in three hundred years is impressive.
But then there's forced evolution.
By wittingly fumbling their invasion of the Federation, they have bottle necked all the inventiveness of a 150 worlds into creation of poorly deployed haphazard antiborg technology which the Borg can laugh at while they assimilate and recognize that they're lucky a competent opposition was not putting them to task with the same tools.
Case in point...
The Borg have assimilated all of Adrmial Janeways Future tech and it will never be a threat to them again.
The next 16 years of Federation genius is moot.