“Feynman converts! According to Frank Wilczek, Feynman eventually lost confidence in his particles-only view of nature:

Feynman told me that when he realized that his theory of photons and electrons is mathematically equivalent to the usual theory, it crushed his deepest hopes...He gave up when, as he worked out the mathematics of his version of quantum electrodynamics, he found the fields, introduced for convenience, taking on a life of their own. He told me he lost confidence in his program of emptying space...(see quote in Chap. 2, "The Gravitational Field")-F. Wilczek (W2008, p. 84. 89)

However this "conversion" is not generally known. Most physicists today routinely use Feynman graphs while promulgating and perpetuating the particle picture of nature, puzzling and paradoxical as that picture may be.”