Some are, but understand they are providing a service and will expect to be paid for that service.
They don’t do much that a person cannot do on their own. Contacting debt holders and negotiating new terms or payment plans can be done individually, though perhaps not with the speed and efficacy of a company that does it for a living.
Setting up a budget and getting friendly reminders to stick to it, these can be helpful for those who lacked the spending discipline to avoid debt to begin with.
There are no “secrets the credit card companies don’t want you to know”