On the nose. But without the hassle of having to pull out a phone to call someone. It's accomplished identically w/ a Bluetooth PTT as well if you have one of those, but they're pricey, $100.
It was more a generalized question vs a specific product even though I included a product. But yes, you are correct in your assertion.
The nice thing about Zello is that if you're someone stuck behind you don't have to worry about missing out on the action on the road. Some people have been crosslinking network radio with their GMRS (though it would work w/ HAM and be legal as long as you fulfill the requirement to identify your station ID every 10 minutes).
Folks were using Zello through Hurricane Harvey which proved to be useful. When the cell towers were running on battery backup, they usually block services like traditional voice calling. Voice calls on VOIP apps usually use dynamic quality depending on bandwidth available but they usually suck because the quality changes chops up audio quality pretty bad. SMS is still good, but not as instantaneous as PTT voice plus you can hear the tone of someone's voice. So this has its place.
Additionally, in New York, after Sandy, our group was providing logistical support to Team Rubicon with assessment and reporting in the Rockaway. We skipped two way radios because there weren't any dedicated GMRS repeaters in the area, but mobile service was plentiful since Sprint, Verizon, and AT&T setup portable cell service trucks in the area. We had 3G data which helped the boots on the ground make status reports to our app which helped the rebuild effort.
