Traditionally, footnotes are straightforward explanations of terms or passages. Tech writers, in their grandiosity, have perverted them to contain randomass tangents that no one really cares about.
Footnotes are mainly straightforward-enough glosses and references, but there have always been digressions (and quite often sniping) in there too. The C19 has some real specimens.
Whereas legal opinions use them either as a citation dump (known as “collecting cases”), as a place to bracket issues that are not being decided, or as a place to put a substantive response to a separate opinion in the case (if you’re an appellate court).
I like footnotes, or in this case maybe we should call "endnotes". David Foster Wallace was known to use them a lot, sometimes he would put footnotes in footnotes.
