I think most ZigBee and Thread chips use 2.4 GHz which limits distance. A lot of water meters are underground on the front yard somewhere so sub gigahertz radio would penetrate better. The modulation scheme of LoRa also allows for greater distance at the cost of data rate. It's also super low power.

Thanks, makes sense.

Interference. It is underground and surrounded by dirt and concrete which sucks for 2.4 ghz absorption. And like three other people said: distance.