Decentralized Reddit & YouTue use GUN's SEA (Security, Encryption, Authorization) and have some of the largest user bases across all decentralized/crypto/blockchain communities. This plugin system (not specific to SEA) for MetaMask could allow all those users to use MetaMask. This is an ugly demo of a hacky prototype.
Note: In the future, for security reasons, there would just be a "Login with MetaMask" button on these sites (Adrien & go1dfish have already told me they're good with this), so that way their SEA passwords are not even leaked into the dApp's DOM.
Important note: Upon first seeing SEA has username/passwords it is easy to think SEA is not cryptographically secure. SEA is cryptographically secure, it does not use the username/password for any cryptography (keys are NOT generated from it, even though many other dApps do this, it is terrible practice), to learn more watch our Cartoon Cryptography 1min animated explainer series: https://gun.eco/explainers/data/security.html !
▶️ DTube
▶️ IPFS