You request a one-time-certificate with a smartphone, then copy it on a laptop (already this is not automatic): once per website or page? That is a lot of certification requests. And that would be to access the content in the www? It creates a dependency stronger than DNS. And there should be full warranty that the issuer and the receiver cannot cross information (of the issued and the received - that would identify the user).
Plus, not everybody has a smartphone. Not everyone accepts Android or iOS at their current implementations. Do those people remain without access to the www?