In 1918, H. Weyl proposed a unified theory of gravity and electromagnetism based on a generalization of Riemannian geometry. With hindsight we now could say that the theory carried with it some of the most original ideas that inspired the physics of the twentieth century. ...The amazing thing to me is that Weyl had a theory similar to the geometric formulations of electromagnetic gauge theory t hat became widely known 50 years later.
Although Weyl’s theory was not considered by Einstein to constitute a viable physical theory, the powerful and elegant ideas put forward by the publication of Weyl’s paper survived and now constitutes a constant source of inspiration for new proposals, particularly in the domain of the so-called “modified gravity theories” .
Despite Einstein’s objections, Weyl’s unified theory attracted the attention of some eminent contemporary physicists of Weyl, among whom we can quote Pauli, Eddington, London, and Dirac. However, the great majority of theoretical physicists in the first decades of the twentieth century remained completely unaware of Weyl’s work.
Weyl's theory did become widely known, but didn't anyone improve it until much later? Or maybe they did, and I haven't heard about it.