The Library of Congress has literally one gazillion public domain photos and illustrations that are free to use for your projects!
www.loc.gov/free-to-use
This portal features content that is free to use and reuse.
Non-artists: please gently let your well-intentioned niche blogger friends know that generating an AI illustration for their posts is not a harmless novelty. There are so many sources for free, eye-pleasing, not-environmentally-rapacious images. Creative Commons licenses, public domain art history.
