I started at 48% capacity and the temp was 60 degrees. Of the 8 Electrify America chargers, there were 4 ID4s all charging at 65-70 kW and four other brands (Hyundai, Lucid, Polestar and Rivian) which were all charging at 132 kW+. Why the difference?
If I saw what you saw, I would blame the car for the slow charging.
However, tracking down the cause for slowing charging is needlessly time taking process at the moment.
At a DC fast charger, your car tells the charger how much current it can receive. Let's call that X.
You can calculate roughly how much current is delivered. In your case, divide 70kW by 400 V = 175 A.
If X is greater than 175 amps, it is the charger,
If X is equal to 175 amps, it is the car.
It appears that the X is primarily calculated using the battery temperature and the starting SoC and probably other factors to less degree but we just don't know.
One way to increase the X is to increase the battery temperature. As SunWizard stated, some EV makers have this function. ID4 does not.
It would be great if the car showed what X is so we can determine where the slow charging problem is. But it doesn't and I don't know if VW has a plan to share this. For now, the only way to get this information is to buy a OBD2 dongle and a Car Scanner app, which is fun for some and too much trouble for others.