Why is it so hard to find a good domain name? Because there are more than a billion domain names. Whoa!
However, only 168 million are active websites. Of that, all of the traffic goes to only a million sites. 167m sites could disappear and nobody would notice. Yes, 1.082B names could be erased and nobody would care.
These domains are hosted on 5.8m computers. A few, such as Microsoft, Amazon, etc., are hosting tens of millions of sites.
Note the spike in registrations around August 2010. That led to a spike in active sites by late 2011. This reached 190m sites and then declined to today’s 168m (April 2016). I wonder if this is due to the shift towards apps? Or WordPress/Wix sites (where millions of sites are subdomains, such as whatever.wordpress.com, something.wordpress.com, and so on)?