acid base - Why are metal oxides basic and non-metals' acidic or neutral

Recently I came across the fact: Metal oxides basic and non-metals' acidic or neutral.

Searching for it, partly my query is solved, as I found:

Metal oxides or $\ce{O2-}$ forms $\ce{OH-}$ after hydrolysis in the following reaction so metal oxides are basic in aqeous solutions. $$\ce{O2- + 2H2O->4OH-}$$

I think this might happen as metal form ionic compunds and non-metals form covalent and some of them may not even react tus neutral.

I've got only a little $5\%$ of the exact reason, therefore I wish if someone could explain the whole process/fact. I considered Arhenius concept.

Note My question is partly answered here, but is not satisfactory.