It's complicated because the internet is a complicated(and I'm no expert)- but, it's not good, but it's not insurmountable. The big issues today are: lots of network attached compute, lots of types of traffic, highly highly distributed network. There are numerous ways of mitigating DDoS, today a lot of it is via BGP route announcement[1] - although we've seen folks using BGP in questionable ways to mitigate DDoS recently[2]. As more and more of the internet becomes software defined (like SD WAN sees large global rollout)[3] more and more granular but non-disruptive control will be enabled. To answer your question about google, their DNS is probably resilient enough to deal with a pretty huge attack but who knows really -- In my dream world we get some good neural networks built and deployed to the edge watching for unusual traffic patterns and disrupt them. It used to be biggest pipes win, I don't know that will continue to exclusively be the case.

[1] http://www.enterprisenetworkingplanet.com/netsp/article.php/... [2] https://www.youtube.com/watch?v=LFJzu0AFDpU (Dyn Engineer gave the talk) [3 ]http://www.rcrwireless.com/20160408/telecom-software/using-s...