> "Ubiquitous" is spelled correctly. Why the "[sic]"?

For what it's worth, '[sic]' doesn't necessarily mean "that was spelled incorrectly", only, literally, "thus": i.e., "that's the way it was in the original; don't blame me." As such, it can be used to indicate misspellings or 'misconceptualisations' ("I know that it's the wrong word, but it's the one that was there"), as nmyk (https://news.ycombinator.com/item?id=17484468) indicates.

To expand on this excellent description, when JadeNB claims that “sic” literally mean “thus”, that is because “sic” is the Latin adverb meaning “thus”. Some people think that “sic” an initialism for “spelling is correct”.

From the context I think the author meant something like "useful for every task" rather than "commonly found everywhere" i.e. ubiquitous.