And depending on the toolchain the author chose, it may also be made in less time than it'd take to hand-roll <li> and <ul> tags into a list.

With a decent editor, hand-rolling <li> and <ul> tags ain't too bad. With a good scriptable editor, hand-unrolling the different options is also surprisingly easy.

I agree. In this specific case, assuming the author had to type-out (or paste) the actual contents of the list, then "hand-rolling" it into a HTML list using a decent editor will be less (probably much less) work than plugging in all that JS cruft.

And, it only happens once, instead of wasting a tiny bit of electricity for computing the exact same thing for every visitor.