Did what? The 1919 experiment didn't prove that light bends. It proved that if you put a massive object, the nearest one we had to hand, the Sun, in front of light, it bends space

No , it proves that all atoms, groups of atoms and parts of atoms ranging from a cannon ball to a photon which has velocity has momentum tending

to maintain the original course it set out on. This course is influenced by the presence of other atoms, groups of atoms or sub atomic particles occupying

the space it travels in. The word bend is a nonsense. The object follows the path which is a function of 4GM/c squared r whereas the newtonian approach is only 2GM/c squared r.

Conventional Newtonian explanation for bending of light is based on photon’s gravitational attraction towards the sun.

In fact, they say a photon has no mass and has mass (hn/c2) only due to its energy (hn). It is hypothesized that gravitation is only between material bodies. Though photon has energy & momentum it does not seem to have inertial & gravitational mass, or else it would have been possible to accelerate or decelerate it. Moreover, if photon is considered as wave, it is not clear as how ( if ) gravity can influence it. There is a debate that the effect could be refraction only. However the lensing effect seen where light forms a ring around a black hole confirms Einstien's theory.