From the original chat that got leaked, Walz had set the group chat up to auto delete messages every week, and 4 weeks in other cases. Official government communication is subject to the federal records act so that chat, which was used to communicate official government actions, was not compliant. If it was just used for lunch dates or something, Hesgeth wouldn't be in this mess.
CISA recommends Signal, but it is not an approved tool to share classified information. That's what SCIFs are for.
If this was aimed at fighting China, Trump wouldn't be tariffing 99% of the rest of the world.
China has the upper hand because USA has turned against all its allies and countries will favor trade deals with the country which is not tariffing them. China will form stronger trade coalitions with the Japan/Korea/Europe and leave America to cannibalize itself.
Signal is an approved tool, and was downloaded on his govt device.
Discussing classified information using Signal is not approved. I'm no lawyer but it probably violates the Federal Records act, as messages were set to expire on a 30 day schedule.
I kid, more real world use cases would be for concept images for a new product or marketing campaigns.