Why do scientists believe that light is made of waves?

Some basic phenomenon of waves is given as below

1) Interference

2) Diffraction

3) Reflection

4) Refraction

5) Polarization

So if we have a wave then it must show the above phenomenon

Initially reflection and refraction were assumed to be particle characteristics so light was assumed to be particle

but after theory given by great scientist Huygen it was proved that it is wave property.

Also light shows the property of polarization, interference and diffraction

so it all shows that light is of wave nature