It's particularly jarring to basically every site I've seen it on which is usually some serious and professional looking open source site.

I wonder why nobody configures this, is this not something that they can configure themselves to a more relevant image, like the GCC logo or something?

Anubis is a bit annoying over crappy internet connections, especially in front of a webpage that would work quite well in this case otherwise, but it still performs way better than Cloudflare in this regard.