Concerning things I look upon the Terms of Use.
The Binance Web3 Wallet Services is a built-in feature within the Application and/or Website which provide you access and use to a self-custodial wallet that uses multi-party computation (“MPC”) technology for managing Digital Currencies and NFTs
To use the Binance Web3 Wallet Services, you must first have an existing Binance Account.
The Binance Web3 Wallet is using MPC technology and therefore there is no private key or seed phrase required. You will not be able to export or import a private key or seed phrase.
In exceptional circumstances and where there’s legitimate reason (determined by Binance acting reasonably) Binance may refuse to co-sign the transaction or activity you initiated. This will prevent you from using your Binance Web3 Wallet to engage in the transaction or activity that you initiated.
Suspicious activity monitoring and holds. In order to comply with anti-money laundering laws, and to protect you and other users from unlawful use of the Binance Web3 Wallet Services, Binance monitors transactions for potential fraud, suspicious activity, and sanctions evasion. As a result, in some cases transactions and accounts may be placed on hold, and the delivery of Digital Currencies or NFTs will be delayed, to permit these processes to proceed to conclusion. In addition, Binance may be required to file suspicious transaction reports, and reports of property blocked, or transactions rejected with the applicable governmental authority.
Those things are such red flags. Requires a Binance account as a prerequisite to use the wallet and also you can not export any keys. And many other things.
As OP said, surely it is not a self-custodial wallet. You did not own the keys, they can block and censor or freeze transactions. The term seems to strongly suggest they own the wallet, not the user. So it should not be categorized as a self-custodial wallet.