There are many considerations and issues related to how a journal financially sustains itself. Some of them include:
Publishing a journal requires a lot of work! This work is acknowledged and compensated in different ways. Most journal outfits find that some of the labor required to run the journal necessitates paid positions, leading to the important question of how one will generate (and maintain) funds to pay for expenses or design alternate means of compensation, such as academic credit, the right to claim service or publication on one’s CV, or citations from peers that may also function as a form of compensation.
When considering whom you will seek to bear the financial burden of providing and sustaining any funding that you need to run your journal, consider how your decision here will align with the values and goals of the journal overall.