That's why they do it. Not very many are willing and/or able to pay the legal fees to fight it, so most of it LE gets to keep. There are actually attorneys/LEO that tour the country to host seminars for other LE agencies where they coach the most effective methods to employ asset seizure. I was able to find one of the videos years ago, where they explicitly instruct them to seek out lower end vehicles/property to seize, because the owners are less likely to be able or willing to defend, because the cost exceeds the value of the items seized, so they are more likely to keep the seized property; high-value autos and such indicate the owners might be more willing to spend legal fees because the cost is still less than the seized property, so unless there is much evidence of a crime attached, it's not worth it to seize. Also, there is absolutely no need to even charge people with a crime in order to seize the property, and in most cases, there are no charges.
Every year in the U.S., the value of property seized by law enforcement exceeds the value of property actually stolen by criminals.