For low volume production items, the plastics are more costly to design than the electronics. Therefore laptop docking stations are expensive to manufacture, especially as they are in use by only a subset of users.
By converting to a docking station that requires a simple small plug for everything, that makes them much cheaper. Instead of making a huge chunk of plastic that the laptop has to click into.
That explains why laptops should have a standardized "docking station" port, not why that port needs to also support literally everything that runs on electricity with the ability to also channel high-current power in both directions.
What's your threshold for "high-current"? USB ports have been delivering about two amps for a decade, and most USB laptop chargers cap at three amps. Even the absolute max of five isn't much higher.
By converting to a docking station that requires a simple small plug for everything, that makes them much cheaper. Instead of making a huge chunk of plastic that the laptop has to click into.