Pinterest is indeed very vulnerable, and potentially already in the crosshairs.
Google just recently launched Shoppable Ads in GIS. [1]
Further, from a user value standpoint, image searching quite often a tool for visual purchase planning. Think clothing, furniture and decor, trips, you name it. That is massively valuable for feeding into audience segment models.
With their launch of Collections ages ago and other things they are doing there, I fully expect to see Image Search become more heavily monetized directly and indirectly in the future.
[1] https://www.mobilemarketer.com/news/google-pushes-deeper-int...