- WiFi calling works in deep inside buildings and hotels where cell signals aren't reliable
- US National parks out in the middle of nowhere are more likely to have free WiFi than a cell signal
- Crappy WiFi costs less than crappy cellular in some countries
- Your home country is never a long distance call on WiFi
On the downside, WiFi access points are terrible at handling more than 50 people. It doesn't help that most phones are set to aggressively pre-fetch data as soon as WiFi is available.