If you are smart, you can build a core of your business and then let yourself be acquihired by the big players if you wish to, why bother with employment at Google unless it's your first job outside university?

Because if you care more about tech than about building products, startups suck. It's a whole culture based on wasting money with inefficient technology (cough cloud) at a ridiculously small scale, both in usage and in complexity.

I've had 20% projects at Google that I spent a few weeks working on and likely handle more traffic than a whole batch of YC backed startups.