3 MW is comparable to 1,000 base 3 kW charging stations for cars or 1,000 households.
Daimler Trucks North America, in one of its job listings, seeks an eMobility Senior Engineer – Vehicle Charging Systems (L5), which would participate in the development of very high power charging systems for electric trucks at up to 3 MW.
“Lead future strategy, concepts, and innovation for next generation advanced charging systems, including strategies for very high power charging up to 3 MW.”
As the electric trucks will be equipped with a battery pack with capacity of an order of magnitude higher than in cars (500-1000 kWh compared to 50-100 kWh), it's reasonable to think that also the charging power will be 10-times higher (in cars the top seems to be 150-350 kW at the moment).
Daimler's goal also seems to be in-line with the recent CharIN announcement about DC fast charging beyond 1 MW (potentially at up to 1,500 V and current of up to 3,000 A).
Tesla, for its Semi trucks, plans a network of Megachargers, which will be rated in Megawatts of power too.