People already know Google exists and whether or not they want to work there. For most people (projecting here) the only recruiting Google has to do basically comes down to: We think you're good enough to have a chance.

For 99.9% of the companies this is not the case.

For example I like working at my current employer and enjoy the challenges compared to earlier employments. But looking at the job postings, I can't see that. It's generic crap about competitive compensation, challenging problems, modern technologies, a flat organization, etc.

If this job posting landed in my mailbox I would skip it. The only reason I applied for this job is because I was jobless and desperate at that time.