The Greek word in that verse is φιλαργυρία, philarguria. The first part, phil-, is where the “love of” comes from, you’ll recognize it from words like “philosophy” (love of wisdom). The second part is -arguria. That’s derived from the word ἀργύριον, argurion, which is a piece of silver or a silver coin, and was also used to refer to a collective sum of money - that is, cash.
Philarguria only shows up once in the New Testament. It’s not terribly common, used maybe 80 times in extant Greek literature by folks like Polybius, Plutarch, and Aristotle (though, like Paul, he only used it once). In context, it always appears in the discussion of undesirable traits, or a lack of virtue on the part of individuals or society. Argurion, on the other hand, is common - hundreds of instances, all referring to individual coins, sums of money, or more colloquially, “silver” (as in a bag of the stuff).
So it’s not a matter of a single word being mistranslated as “money” instead of “capital.” The word philarguria literally means “the love of silver coins,” and was used metaphorically to decry avarice - that is, extreme greed for wealth or material gain.