There could be websites that Phantom has blocked and users may have connected their wallets to these websites and didn't revoke because they didn't know these websites are compromised. Sometimes these compromised websites could affect the users with delay and drain/scam them.
What if Phantom had a revoke tool within the app to show if any of the trusted apps within their account is blocked by Phantom and allow them to revoke from that tool for Phantom blocklist specific.