If you have direct control you need far less automation and can potentially solve more problems at sea or change destination as needed or retrieve it faster if

If you have direct control you need far less automation and can potentially solve more problems at sea or change destination as needed or retrieve it faster if it breaks down by telling you exactly what is wrong, and it requires less skills to build all the hardware. Your entire radio communications setup is as close to plug-and-play as it gets and it both looks like "legitimate" radio signals and is far less likely to detected on the ground as a remote control link since it is using phased array antennas pointed at the sky rather than at the horizon. You also have to remember its not like they are building tons of identical subs and moved an entire fleet over to starlink. They could have a dozen very different setups running with just a few guys tinkering around with whatever devices are easy to obtain under the radar, and it prevents single design vulnerabilities from collapsing your entire sub delivery supply line at once. Even if it only evades enforcement a single time by being novel, the cocaine it delivers out values whatever hardware and work it took to setup in the first place.