That was largely the point of the Fabian strategy, was it not? Similar to the concept of a Fleet in Being[1], maintaining a functioning force is protected, but still able to threaten the other side constrains their options and makes it harder for them to achieve victory. Hannibal may have never lost in Italy, but he was nonetheless prevented from winning either. Though the main armies could only do so much to keep him from taking objectives, it made it difficult for him to maintain control over them. Notably, Hannibal had difficulty securing lasting control or alliance with many of the Italian city states, and those he did control often required losing some of his limited forces in order to garrison, otherwise they risked being retaken by the Roman army once Hannibal had moved on.
[1]https://en.wikipedia.org/wiki/Fleet_in_being