FWIW, I gave YaCy a try a while back, and I agree with the article on that one. Shit tier results that make ancient AltaVista look good. Might be fine for intranet search. I like the idea of its distributed hosting, but pass on this one.

Other poster mentioned SearXNG, and while I haven't delved into that too much, it's probably worth a check. Pass on YaCy.