I remember reading the linked Dan Luu article [1] when it came out. It was much more even handed in addressing the question, in my opinion. In particular, he includes comparisons and analysis of specific queries. For some of them (e.g. “download YouTube video” or “ad blocker”) none of the search engines were even passable.
That’s the kind of side by side analysis you should be looking for.
The second point when people talk about Google getting worse is, is the Internet just getting worse? Maybe it’s both? Google’s interests aren’t aligned in the same way Kagi’s are, but if Kagi can’t keep blogspam out of its search results why are we blaming Google when they also fail to do so?
This is a genuinely hard problem and it’s interesting so I might take a look into it when I get a chance.