> they [...] figured out their most profitable course of action is to enshittify their flagship product
I think Doctorov is getting this entirely backwards; Google would love to provide good search results, but there's just one Google, and there's millions of people out there trying to make SEO spam. Most bloggers are just writing whatever posts they feel like writing, while content farms explicitly optimize for articles that rank highly in search. The outcome is inevitable.
To be clear, I think Google could (and probably has historically) spend more on improving search, I wouldn't be surprised if they decided that this isn't profitable for them, but I don't think there's anybody at Google who explicitly wants search to be bad.
Kagi isn't good just because it is good, it is good because it's small enough that nobody really optimizes for ranking high on Kagi.