Earlier quoted context omitted.
In short; yes. I think it's fair to say that google aren't going to run out of engineers if they implemented a completely rigid payment structure. Firstly, their pay is very high compared to the industry and secondly they attract the best engineers by reputation more than anything else.
What happens in a few years when the best engineers start leaving because they can negotiate higher pay elsewhere? If they start to get a reputation as merely good, but not the best, not where the exciting work happens?
Personally I wouldn't imagine those things are well correlated at all. In my experience the best engineers have stayed around long after it was obvious that they could get considerably more by changing jobs (and sometimes changing back again).
That aside, I think it would be entirely possible to set this up transparently enough that an engineer can see their future compensation and thus see how many years ahead they are jumping and can make their own judgement about whether it's worth moving to a company where their future compensation will likely change in the usual haphazard way.