Why Brave does not use its internal wallet for the Rewards

[SmartyAadi]

It is because of governement and financial regulations. Blame them, not Brave.

Change rewards wallet to Brave wallet

In order to comply with current financial regulations (such as FinCEN and OFAC requirements, or equivalent regulators outside the United States), Brave Rewards payouts at this time must first go through a regulated custodian (like Uphold/Gemini). Note that once you receive BAT into your custodial account, you can always withdraw it on-chain to your Brave Wallet.