IMO one of the great things about eg semantic forms in HTML is that instead of building a GUI you essentially write a machine readable description of an API tha

IMO one of the great things about eg semantic forms in HTML is that instead of building a GUI you essentially write a machine readable description of an API that a GUI gets generated from in a way that allows for optional styling. When used correctly it's hard to imagine a better way to provide access to a remote service. Of course it's rarely used correctly when money is involved but I think that's a human thing that happens and the technology can't change it.