Agreed with Andrew. You don't have to pay. The choice of open access or not is the authors. I would argue that the only way that authors are 'forced' to pay is if they 'have to publish at any cost' i.e. a highly competitive market, contractual reasons, keeping up with peers etc. However, this (for many) often means the temptation of submitting to low-quality and/or predatory open access journals. This is not recommended at all. They cost the author and there is no benefit. No-one reads or cites such material.
The concept of paying for publication is relatively new. Most traditional journals offer free publication of your paper. But you have to remember that you do give away copyright to the publisher, which means they own the article and can charge customers to access the article. Since the concept of open access appeared, companies have simply switched where the money comes from. Instead of charging a subscriber to access an article, they charge the author (or their institution) to make their article freely available. So as an author you have to weigh up what is the best option for your article, restricted access to subscribers or free access to everyone.