pranav r. phatak wrote:
"all the standard opearting systems have TCP built in"

and phillip m gallo
"you will collect these meters into an agregate collector"

These are the two "Killer" reasons to put TCP/IP into your embedded system: because it is easy to network lots of devices together, and because of its very widespread support.

Adding a "telemetry" or remote monitoring interface to a utility meter, a vending machine, etc, is only a very small part of the total system - you also need a comple "Back Office" setup to collect all the data from lots of utility meters, vending machines, etc, and process this in some useful way for the overall business.

"equipment with a decent userinterface would use an Arm chip or similar?"

That's another good reason: with TCP/IP, you don't need to build your own user interface onto the embedded device; you just implement a web server, and this can display on a browser running on any host system!