I agree but there is https://github.com/Dan-Q/ibiblio-icon-archive/tree/main/icon... and then you can put a . (or a .gif) in the Finder search box (or do find -type f -exec mv)

I really love that the source-extension icons are all different, and resemble the files contents - .c indentation, .h mostly linear, .s assembly instructions, ".o" bits