IMO, the reduced output of a team of specialists vs a team of generalists has less to do with generalists doing better work, and more to do with it being impractical to hire specialists at lower levels of scale - and higher levels of scale are less efficient.

A 3 person engineering team doesn't want to hire a specialist DB admin who knows Postgres back to front but can't code. A company of 1000+ engineers might, because they might have problems that require that expertise.

But any engineer working in a company of 1000+ engineers is also subject to friction resulting from resource allocation inefficiencies, communication overhead, regulatory compliance, etc: the reduced output from those factors has little to do with the specialist engineers doing worse work, and more to do with them working at the size of company that can afford to hire specialists.

(You could make the case that buck passing is an example of resource allocation inefficiencies, as it is often accidentally or purposely enabled by company management, but nonetheless, that's not a generalist vs specialist tradeoff.)