Where courts make a "thing" rather than a "person" the subject of a case, this is called "in rem" (which is Latin for "against a thing").

The legal theory which underlies civil forfeiture is "in rem jurisdiction" where it's not the owner, but rather the property, which is the defendant in the case. If the case is at a Federal level, then it will be something like "United States of America vs. $50,000 in United States currency".

The standard of proof is not at the criminal standard ("beyond a reasonable doubt") but instead the civil standard ("preponderance of evidence").

Right, so the sibling reply was correct. The person I was replying to said that the "problem" they were trying to solve when they invented the practice in the 1800's was things like seizing smuggled goods off a ship, where the owner is overseas and you don't have an extradition treaty with them.

So, seize the goods in anticipation of convicting the owner. Make a law that says the owner can apply for a writ, and a case must be made. If the owner doesn't show up, then the goods are abandoned property. That allows the case described to be prosecuted, while not opening up the insane abuses we've all heard so much about.