It produces cross-functional contact, which is the actual objective
Nobody signs off a summer party budget for the catering. They sign it off because the organisation works better when people have weak ties across boundaries. Deliberately mixed quiz teams and a game about the room are direct interventions on that, and they're considerably cheaper than the alternative of hoping the seating plan does it.
It doesn't punish the quiet half of the company
Standard icebreakers select for confidence and reward the people who were already going to network. A phone-based experience removes the audience from the act of participating, which changes who participates. Organisers consistently report this as the surprise.
The prep cost is an hour, not a supplier relationship
External team-building providers involve scoping calls, quotes, contracts, a facilitator's travel and a day of everyone's time. Writing twelve good quiz questions and printing a QR code is a different order of commitment, and it can be decided three weeks out rather than three months.
It gives internal comms something to work with
The photographs colleagues take of each other are better recruitment material than anything staged, because they look like a place people actually enjoy. A company event that ends with a downloadable library of them has produced a second deliverable beyond the evening itself.
It repeats across regions and quarters
If you run four regional summer parties or a kick-off in every market, the same format travels without a facilitator having to. That's the case the business packages exist for.