Police budgets are completely out of control. Defenders will often quote base salaries and it's almost always intellectually dishonest. Overtime can 2-3x that base salary. It gets worse too because, depending on the police department, your pension is based on how much you earned your last year so people in their last year get to take all the OT.
And beyond that they're so awash with money that they're turning into paramilitary forces.
And on top of that we have a regime of legalized theft aka civil asset forfeiture. Often the police departments get to keep some or all of what they seize. They'll often get a cut of ticket revenue too such that cops will have quotas of tickets to write.
Combine the two and you end up with so-called "forfeiture corridors". You might find that drugs go one way but the cash goes the other and they'll only police the cash direction with excessive stops and tickets to seize as much acashn as they can get and then the burden is on you to prove the cash is not the proceeds of crime.
You say departments get to keep civil forfeiture proceeds, but the truth is individual officers often take that home. There are many cases of US police using civil forfeitures to buy themselves luxury items such as premium trucks for personal use, Super Bowl memorabilia, premium dog food for their pets at home (some actual examples). The money doesn’t just go back to police service funding.