The linked tweets imply that this decline in search results was Google's choice, led by desire for further monetization or exec incompetence, but I think Google is simply facing an impossible task.
Receiving an arbitrary question and finding the most helpful site for that question out of the entire web is already nearly impossible.
Now consider the above problem, except the sites you have to search are highly adversarial. More precisely, the internet is roughly divided into people who post useful content and have little interest in SEO and those who only care about SEO and clicks and not about creating useful content. The latter are more motivated and have more resources. For every useful site, they can take that site and create 100 of their own copies with the same content, more aggressive SEO and their own ads.
How is Google, or anyone else, supposed to navigate this landscape?
Receiving an arbitrary question and finding the most helpful site for that question out of the entire web is already nearly impossible.
Now consider the above problem, except the sites you have to search are highly adversarial. More precisely, the internet is roughly divided into people who post useful content and have little interest in SEO and those who only care about SEO and clicks and not about creating useful content. The latter are more motivated and have more resources. For every useful site, they can take that site and create 100 of their own copies with the same content, more aggressive SEO and their own ads.
How is Google, or anyone else, supposed to navigate this landscape?