The first one, the article touched on obliquely:
> Back in those days of high adventure hosts were far more than mere pets, they were golden temples where crusaders came to worship speaking prayers of code. > > Today, servers aren't even cattle, servers are insects connected over fast networks. Centralization is not only possible now, it's economical, it's practical, ...
"Back in those days" users were administrators of one sort or another because that was the barrier to entry. But administrating systems sucks, even if it's just a PC. The rise of server-less is just another testament to this: being able to outsource the boring, tricky bits to experts is great as long as the principle-agent problem doesn't rear its head too often.
The second issue is that distributed (I suppose some people might call them federated) identity systems don't work very well. Look at the vast gulf between the spam problem on Facebook and the spam problem with email.
If you've signed up with a centralized identity system, it's pretty convenient to use a bunch of services synced up with that identity: all of the social media stuff is probably the tip of the iceberg.