The SIWE movement probably will win out, imo. Brave already supports it natively, and services like ENS are growing in popularity and use cases. And MetaMask itself is already at 50 million installs. Most other smart contract blockchains are Ethereum compatible, so you can use the same account (via MetaMask or wallet of your choice) across blockchains pretty easily. It's also dead simple to implement as a web developer, and it's a pleasure to use as a user.