Well, for starters, they collect those massive interest payments each year. They also saddle the companies with expensive, long-term consulting contracts which extract even more money. And if/when the company goes bankrupt, the courts often give financiers an equity slice of the new post-bankruptcy company.

The idea is usually to slash close enough to the bone that the company survives, but 100% of profits go to debt servicing. But this doesn't make for a company that's resilient to economic turmoil (or one that can invest money into growth). So the contingency plan is to ensure that they are first in line in court.