Inverse relation of dependency

You may use patron in many circumstances like this.

patron = a person or group that gives money or support to a person, an activity, or an organization

Cambridge

patron = one that uses wealth or influence to help an individual, an institution, or a cause

Merriam Webster

The word has a long history, going back to Roman times. Your example of a dependant may be regarded as client:

Clientship, Latin Clientela, in ancient Rome, the relationship between a man of wealth and influence (patron) and a free client; the client acknowledged his dependence on the patron and received protection in return. This sort of relationship was recognized in law as early as the 5th century BC; by the 1st century BC it had become hereditary. Freed slaves were automatically clients of their former owners. The patron might support his client in the courts or supply him with daily food, often converted into cash (sportula). The client was expected to show deference to his patron, especially by calling upon him each morning (salutatio) and by aiding him in his private and public life.

Britannica