I suspect you're correct. A good friend of mine had a theory that the internet in "common" use would grow smaller horizontally and larger vertically as time went on, and that seems to be panning out.
Back in the day "common" users of the internet were only the tech elite at universities - as such normal users of the internet would be fiddling with it at the fundamental protocol level just as much as they would be using those protocols to communicate. These were the days that RFCs were being rolled out left right and centre for the common communication protocols that were being established.
Then, as it became more established, people didn't need to contribute to those protocols; they just used an established subset of them. So they'd use HTTP for websites, FTP for files, SMTP & POP3 for email, Telnet for remote comms, etc.
Further down the line, most of those protocols started to disappear in common use, and websites over HTTP started to be used for pretty much everything instead.
...and now we're at the point where most individual HTTP websites are dying out, being replaced by nearly everything being done on just a few key websites (Wikipedia, a handful of news websites, Reddit, Twitter, Facebook, etc.)
I just wonder if the trend will continue, and if so what form it'll take (will there be one website to rule them all? Will the types of websites eventually disappear until everyone just uses Twitter for everything?! Who knows...)