There are several decentralized schemes where the identifier is cryptographically bound to a private key, none of which I can use in my browser. Since a majority of people use a handful of public DNS resolvers anyways, these resolvers could deploy split DNS for a special-use domain, let's say ".did" (short for decentralized identity), and resolve this special TLD differently. This way people do not need special software to access websites on a ".did" domain.
Maybe DNSSEC could be mandatory and your domain name is the key digest from the DS record, although this prevents key rotation while maintaining a stable domain name.
Actually, tor is also not browser centric at all either. It does TCP (if not more), so any protocol will do. Proxy is typically a SOCKS interface IIRC, so any client will often do as well.