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An about page often describes more information about the person (or organization) that a site represents, or that a site is created by, than on the top level home page.
For different people/organizations, an about page can indicate different things and more than just the home page. For example, some use it to identify interest, contact data, a formalized bio, etc.
Discovery from home page
One of the issues is that, when you are sharing your details with others, you usually do not share the About page. You share the top level page, from which there is usually a link.
There is likely some basic information on that top level page which the About page expands on.
There is no way to automatically discover that expanded set of details.