Looking back at the 60-plus years of computer systems, we can see a pattern of design preferences. That pattern is an initial preference for vertical design (that is, a complete system from top to bottom) followed by a change to a horizontal divide between a platform and applications on that platform.
A few examples include mainframe computers, word processors, and smart phones.
Mainframe computers, in the early part of the mainframe age, were special-purpose machines. IBM changed the game with its System/360, which was a general-purpose computer. The S/360 could be used for commercial, scientific, or government organizations. It provided a common platform upon which ran application programs. The design was revolutionary, and it has stayed with us. Minicomputers followed the "platform and applications" pattern, as did microcomputers and later IBM's own Personal Computer.
When we think of the phrase "word processor", we think of software, most often Microsoft's "Word" application (which runs on the Windows platform). But word processors were not always purely software. The original word processors were smart typewriters, machines with enhanced capabilities. In the mid-1970s, a word processor was a small computer with a keyboard, display, processing unit, floppy disks for storage, a printer, and software to make it all go.
But word processors as hardware did not last long. We moved away from the all-in-one design. In its place we used the "application on platform" approach, using PCs as the hardware and a word processing application program.
More recently, smart phones have become the platform of choice for photography, music, and navigation. We have moved away from cameras (a complete set of hardware and software for taking pictures), moved away from MP3 players (a complete set of hardware and software for playing music), and moved away from navigation units (a complete set of hardware and software for providing directions). In their place we use smart phones.
(Yes, I know that some people still prefer discrete cameras, and some people still use discrete navigation systems. I myself still use an MP3 player. But the number of people who use discrete devices for these tasks is small.)
I tried thinking of single-use devices that are still popular, and none came to mind. (I also tried thinking of applications that ran on platforms that moved to single-use devices, and also failed.)
It seems we have a definite preference for the "application on platform" design.
What does this mean for the future? For smart phones, possibly not so much -- other than they will remain popular until a new platform arrives. For the "internet of things", it means that we will see a number of task-specific devices such as thermostats and door locks until an "internet of things" platform comes along, and then all of those task-specific devices will become obsolete (like the task-specific mainframes or word processor hardware).
For cloud systems, perhaps the cloud is the platform and the virtual servers are the applications. Rather than discrete web servers and database servers the cloud is the platform for web server and database server "applications" that will be containerized versions of the software. The "application on platform" pattern means that cloud and containers will endure for some time, and is a good choice for architecture.