Why aluminum is an amphoteric metal, is it its own property, or can it be explained?

Most people think that aluminum is an amphoteric metal. The amphoteric nature of aluminum is not acidic or alkaline, but metallic and nonmetallic.

Aluminum can react with dilute acid to replace hydrogen, which is metallic; It can also react with strong alkali to produce nonmetallic AlO2- (metaaluminate).

But when aluminum reacts with strong alkali, it is; Aluminum reacts with water first and then with alkali solution, so some people say that aluminum is only metallic, not amphoteric.