It seems structural complexity, as described in the text, is preferable because doesn't involve an argumentative leap. Any new ontological entity could hugely simplify an argument. However, that is done by moving argumentative steps into the premises.
Consider, for instance, what happened with the discourse around cryptocurrencies lately. The term blockchain was a part of the argumentation, people would try to understand it's role and fit it into their explanations. Some time ago, however, the term seems to have been upgraded from a chain of blocks to a Blockchain with capital B and a whole new place in the ontological structure of the world. Suddenly a Blockchain based technology was an explanation in itself that would guarantee the trust to a system.
Now one can explain Bitcoin as a Blockchain based technology that implements currency. Well, this has not made the explanation simpler. We have only encapsulated knowledge and labeled it. In Bitcoin case the problem is not so big, but this procedure can cause a lot of misleading.
We can create any sort of thing as a new ontological entity in our argumentation, creating false concepts and useless categories. Consider, for instance, the category Economic System. Capitalism and Socialism should be two Economic Systems, what makes them to instances of the same class. This is, however, completely misleading. To say that Capitalism is a way to organize society is misleading because it is precisely not to organize society.
Ah, yes, by turning the argument into a premise, you're effectively 'blackboxing' knowledge, so it doesn't get criticized. You're quite right.
We could cite lots of examples where new ontological constructs better explain reality. For example, the development of mathematics is fundamentally a development of ontology. But because it is such a powerful tool, it can be used for devastating effect. And we could cite tons of examples of that, too.
Believing an agent of government is ontologically different from ordinary people is necessary for the establishment of taxation and coercion. The idea that races and genders have certain ontological differences (souls, for example, or authority) has been in the core of racism and sexism. The paradox of the Cosmological Argument can be resolved by creating a new ontological category: God (the immovable mover). Because a god can 'resolve' the paradox, it inhibits further scrutiny and the realization that the whole argument is a fallacy.
Erroneous ontological premises can lead, and often do lead, to cognitive dissonance. It's funny how ideas well established in natural sciences have a talent for being misinterpreted and misused in social sciences.