That is true, but what's also true is that it's _way_ easier to get promoted beyond L5 as a manager, and darn near impossible to get promoted beyond L6 as an IC. Google values managers more, just like any other company. That's why you see like 7 layers of management there by now and directors reporting to directors and VPs reporting to VPs: people want more money but can't get to the next level as ICs. Fun fact: when I left Google, I was 1 level deeper in the hierarchy than I've ever been at Microsoft, a company that at the time I left was twice the size of Google I left 7 years later.
I wouldn't say it's easier to get promoted in the sense that the work is easier. A company with 85,000 employees needs a lot of managers (who themselves need managers, and so on), so there's definitely demand. But that demand need not change the stringency of the job requirements.
