Agreed. With the amount of time it takes (likely more than their sentence) for a cop to drive a suspect back to the PD, there is no incentive for criminals to follow a cop back to the PD.
This would benefit both cops and criminals, giving lower-rank cops the opportunity to gain more exp and criminals the opportunity to avoid longer sentences. It would also help reduce the "us vs them" toxicity between criminals and cops as there are more opportunities to communicate and play together despite being on opposite teams.
If taking criminals back to the PD is used more often, this could also give criminals a new activity - breaking a suspect out of custody during transport. Lockpicks could be required to break out of the handcuffs.