Supporting an IP layer in a protocol stack does consume resources that could be applied elsewhere. However, there are key benefits in building an IoT system that allows devices to communicate over TCP/IP. We will begin by enumerating these benefits; however, it is the role of the architect to balance the cost of these services and features against the impact on a system.
From an ecosystem point of view, regardless of the protocol used at a sensor level, the sensor data will ultimately be fed into a public, private, or hybrid cloud for analysis, control, or monitoring. Outside of the WPAN, the world is TCP/IP-based, as we see in WLAN and WAN configurations.
IP is the standard form of global communication for various reasons: