[keithxm23]

A lot depends on your use-case and the kind of website you're using this on.

I would find this very useful on a site like Wikipedia where I often know the section I want to jump to before landing on the page. (e.g. I want to see the number of goals Messi has scored each season at Barcelona and I know there's always a table at the bottom of most wiki articles regarding historical stats for soccer-players). I could see from the mini-map where the tables are jump straight to it.

Like you said, the the text is too small to make out where you're going or navigating. But most often I find myself visiting sites that I've visited in the past and for those I have a good mental image of what the page already looks like. I can use the hints from a minimap to jump to the relevant section of the page.