Let's run traceroute to see the path the packet takes to reach the destination.
We have done traceroute on kplabs.in and I have attached the results in the following image:
If we look into the preceding output, just to reach kplabs.in, the packet had to traverse 20 different nodes across the world.
This means that the data (login/password) we send travels through all these nodes. If an attacker is monitoring one of these nodes, then sensitive data can get leaked or may be altered in transit.
This is one of the reasons why cryptography plays a very significant role and we have an entire chapter dedicated to it.
Having said this, in designing defensive network, people and process are much more important than products that are used in network security. However, the components are very necessary as well.