G is not a search engine anymore.
Just because Google is now attempting (not yet successfully, in my opinion) to detect and supress "low quality" websites it suddenly isn't a search engine?
Someone is searching for detailed, authoritative information about widgets; they send a query to Google and they get back a list of documents that are "relevant" to the query.
99% of the web pages about widgets were created for Google, and the vast majority are either a copy of an original article about widgets, or some sort of autogenerated mashup of text that includes widget related text, or a cheaply produced mini-article that superficially talks about widgets, published by a content farmer.
So, which of these documents does Google list at the top? The one that some algorithm decides is the one that is most "relevant" to the way the user worded their query?
If they try to push the worst of the junk documents down the list, that means they are no longer a search engine?
There has to be manual reviews of sites
No question, humans can judge quality better than a machine, but they are a costly input. Google uses human judgement to "seed" processes, and evaluate processes that are largely automated. Even if they could afford to do so, Google isn't going to study each of our sites and give us a grade; more importantly, they can't afford to hire humans to look at the millions of junk sites that crank out billions of pages of garbage every day. It's those "low quality" sites Google wants to suppress.
The problem isn't with their intentions -- which are good -- but with the execution (which is inadequate) and the fact that everything they do has such an outsized impact on the entire internet.
The core problem is that Google is too powerful -- so even their well intentioned efforts create enormous collateral damage.
We would all be better off in an environment in which Google were no longer the pipe sending 70-90% of the traffic to so many websites (depending on the niche).
But, currently Google is effectively a single point of failure for the entire internet ecosystem, so even a well-intentioned attempt to suppress "low quality" can cause widespread havoc and destruction.