Royalty Free is a term used in industries where content (photographs, music, books etc.) are published and sold. It dictates that the media can be downloaded and used as you want. The original owner retains the copyright to it but the downloader may use it in a variety of ways. Sometimes it is for a copy of the original media and other time there might be a size stipulation or use stipulation. Most artists or content creators usually offer the "less than best" and "much, much less than best" for royalty free images. I have not done that here. Many of the images are some of my best works.
I first started uploading images online to sell in 2007. At first, at my website I always had a gallery that was free, and the images were not watermarked. Due to the nature of the internet some people were very irritated that I was "giving away my work" and angry at me for doing that because they thought people would expect them to do the same thing.
I have been in situations that I had no money to buy stock images and appreciated the royalty free images I found online, so I kept the free galleries up as long as possible.
At this time in my life, it serves my interests and life to offer the bulk of my work royalty free, so I have done that.
There are multitudes of ways to market things and multitudes of ways to make money or no money from your work. Every single human has different living conditions and needs for their life, safety and care. It is up to them to decide how they want to proceed with their lives. They may never be a billionaire, but they might achieve their goals and live a beautiful, healthy life anyway.