This reminds me of posts from 10 years ago where "the future of search of social" (this post says "user-centric" instead). Even Google feared that outcome (given the then-meteoric rise of Facebook; oh how the turns have tabled). Personally I find the musings in this post to border on nonsencial.
But here's the interesting part: certain ideas are sticky just people want them to be true. The core one here is that "search is broken" or even the lesser "Google is getting worse". It's one many on HN like to push. I don't think theres any quantitative empirical evidence of this. It's people wanting it to be true and you'll see it on every thread about DDG (as one notable example).
Silicon Valley is littered with the corpses of "Google killers" who seem to have all fallen into different versions of this trap.