I'm consistently amazed at how well the likes of FB, Google/Youtube, AWS and Netflix actually work by those organizations. Yes there is the occasional down time where things are partially down... just the same that they manage to handle the sheer volume of traffic is truly impressive. Most businesses don't really need more than what a large co-located server offers in compute and storage...

To create a system that services requests from hundreds of millions of simultaneous users throughout the world is genuinely impressive.

Of course it does have its' cracks... The mobile browser interface is more and more gimped as time passes, and the comments for posts that don't have hundreds of replies is equally borked (don't see all replies, or your own half the time). "Eventually Consistent" has it's price... but the reward is handling hundreds of millions of users at one time.