Sorry, you are right. That being said, it's a remarkable approach to messaging. E2E, decentralized, can be used over WiFi, Tor, Bluetooth (In case there is a blockage)[1]. Has been pentest reviewed[2] before the first release.

Or to sum up:

"Briar is a messaging app designed for activists, journalists, and anyone else who needs a safe, easy and robust way to communicate. Unlike traditional messaging tools such as email, Twitter or Telegram, Briar doesn't rely on a central server - messages are synchronized directly between the users' devices. If the Internet's down, Briar can sync via Bluetooth or Wi-Fi, keeping the information flowing in a crisis. If the Internet's up, Briar can sync via the Tor network, protecting users and their relationships from surveillance."

[1] https://briarproject.org/how-it-works/

[2] https://briarproject.org/raw/BRP-01-report.pdf