If network-bound apps are rare, then you believe that mobile apps and web apps are rare. Both are, combined, likely to make most other app types seem rare.
You seem to be confusing client and server. When people say I/O-bound or CPU-bound they usually refer to servers.
And most clients aren't network-bound either. They are server-bound (i.e. they spend more time waiting for the server to create a response than for the network to transfer it).
No, I'm not confusing anything. I can see why you would believe that, based on what I assume you made as inferences.
There are plenty of mobile and web apps that are network bound in this day and age. Many games, for example. That's just the obvious choice of example.
games are more sensitive to network latency, not throughput.
The phrase "I/O bound" is typically used in the context of throughput limitations, not latency. The issue of network latency is more complex than simply the network level as it involves the whole software stack in the equation.
