I hadn't realized that Bing image search still lets you link directly to the Image URL, not just the page it's hosted on. Something Google stopped doing a few years ago in response to content platform complaints.

OK, I'm definitely switching to Bing Image Search for images.

Per OP... they do seem to have a public domain/CC search limit feature too. I don't know how well it works. (I'm not sure how either it or Google identify CC/public domain content. Is there an opengraph tag?)

https://www.bing.com/images/search?q=dogs&qft=+filterui:lice...