You are familiar with the device to answer questions the  attendees may have

You can test the devices and games to ensure everything works

You can be sure the  players receive the device with a full battery

Most people do not own tablets. You can provide a bigger screen and view the  games for teams with tablets.

Initial investment to purchase the devices

Maintaining the devices system software and all the apps on them

Charging batteries

Insuring the device life expectancy with weatherproof bags or shells

TRansporting and dividing the devices before the game is an extra task.

You have to renew the devices in a couple of years.

No need to invest into buying tech

No maintenance tasks related to the devices

In big events quite practical

During the team games when one device battery runs empty or is not suitable, then the other team member has a replacement

People are familiar with their own devices

During the event you get questions about the device models you are unfamiliar with

Some devices have too outdated software or hardware to run your event

Phone batteries run empty faster than tablets, so you have to provide battery packs during the game

Extra time to instruct attendees to download the apps needed for the game