I always figured this would be the path I'd take - found a successful startup and get bought by Google. Instead, the startup floundered and I got hired by Google anyway.

Regardless of how tough it is to get into Google, founding a successful startup is still tougher. Plus, if you're only looking to get bought by Google, you'll be overlooking many other options, and will decrease your negotiating leverage accordingly. If you want to work at Google, apply to work at Google, and if you want to found a startup, found a startup. But don't confuse your motivations for the two of them, because you'll be doing a disservice both to your startup and to your chances of working at Google.