Essentially that the idea that people can hold 7 + 2 things in their head simultaneously is basically true such that when your tools make a demand on your attention it subtracts from the attention you can put on other things.

There are many sorts of struggle. There is struggle managing essential complexity and also the struggle, especially in the pre-product phase, of getting consensus over what is "essential" [1] When it comes to accidental complexity you can just struggle following the process or struggle to struggle less in the future by some combination of technical and social innovations which themselves can backfire into increased complexity.

Google can afford to use management techniques that would be impossible elsewhere because of the scale and profitability of their operations. Many a young person goes there thinking they'll learn something transferable but the market monopolies are the one thing that they can't walk out with.

[1] Ashby's law https://www.edge.org/response-detail/27150 best exemplified by the Wright flyer which could fly without tumbling because it controlled roll, pitch and yaw.