This is the 17857th most frequent Russian word.
усложнить
To make more complicated or difficult.
In this sentence, "усложнить" is used to describe the action of making the task more complex.
Я решил не усложнять задачу, чтобы её проще было решить.
I decided not to complicate the task so that it would be easier to solve.
Here, "усложнить" refers to the effect of making comprehension more difficult.
Его объяснения только усложнили понимание темы.
His explanations only complicated the understanding of the topic.
In the given context, "усложнить" signifies adding superfluous elements that increase complexity.