The austerity approach to page performance works for Google because they control their whole stack, they have world class devs to can devote time to fine tuning

The austerity approach to page performance works for Google because they control their whole stack, they have world class devs to can devote time to fine tuning products, and their bread and butter is in small, focused tools (search is an input and a list). Other big tech companies like Facebook or Netflix don't follow Google's approach, because most products are sprawling, and built by many teams and many engineers. Keeping a small, tight, codebase under those conditions doesn't work. Contrast Never Slow mode with what the React folk are doing with React Fiber. They have rewritten their engine to allow JS execution that doesn't block the main thread. This is much more pragmatic than setting budgets and simply telling devs to try harder.