Ctrl Alt Del, Life Coaches are certified and you should not trust one that isn’t. You can’t learn how to coach by reading books alone, there is a lot of work involved in the course and if you do it with commitment you get certified if you don’t you fail. So don’t assume it is a “made” up profession with no oversight, it isn’t. There are many social workers who I now see place the title Life Coach behind their name.
And again different people need different approaches and different types of help. Anyone with a psychiatric disorder or in need of medication will not go to a LIfe Coach their first line of therapy is an MD. If they need “talk” therapy they will go to a social worker, if they need to move forward they will go to a Life Coach.
I take offense to your assumption that a Professional Life Coach is a person who reads a lot of books. That is demeaning and disrespectful. In addition maybe you should not blame the “coach” but your family members who were not committed to making changes or making better choices in their lives.