You are not getting the point! As you said in order to withdraw connect Brave wallet to another wallet Or lose all your earnings, right? Why there is a need for two wallets and if it is then why does one have to suffer? Also, how to get back all the Bkmrks and login credentials that we stored trusting Brave?
If you had a sync chain you can add this device back to retrieve them.
Because Brave as of now Brave doesn’t have a money transmitter license which is required for giving out BAT. Also a lot of regulations from governments which will make it too complex got Brave. Also Brave will need to do KYC.