Why is receiving $50$ links from $5$ different websites better than receiving $50$ links from the same website?

Many Links from the same website are a signal of black hat SEO

Links from $5$ websites means a higher link diversity than links from one website

Links from $5$ websites are more likely to generate social sharing

Search engines only register one link from any given domain, so they only count the $50$ links from the same site as a single link