Also, inlining CSS prevents its caching, so the first page load may be faster but subsequent ones will suffer from that if the amount of code is fairly large.
It’s a pointless micro-optimization.
When your site has a large audience, every microsecond counts. Especially when you don't have someone bankrolling for your traffic. Speed plays an important part for SEO and UX.
There are so many other, bigger, better, wins to focus on first.
Considering anything Google does as useful for the average developer - even at a reasonably large company - is like thinking pizza delivery guys should emulate UPS: it’s a misunderstanding of context.
That's a damn lot of CSS