Brave doesn’t do that. It’s not as secure. Accounts get hacked all the time, especially as people often reuse usernames and passwords.
Sync code changes daily. Brave has announced Sync is not intended as a backup. It’s meant for you to connect to your devices and then have them maintained. You shouldn’t need to constantly add and remove devices.
You may also want to check out PSA: Current FAQ - #36 by Saoiray