You're not entirely wrong however. There is effectively one atmosphere differential at sea level, but framing the difference that way is at worst intellectual dishonest, or at best a rather naive understanding. In actual reality there is a very long tube, and all the surface area is under pressure. In metric is 10,000 kg per square meter, multiplied by all the square meters down the length of tube. Of course this simplified understanding ignores the weight of the transport capsule inside, which causes a momentary higher differential. And, the hyperloop won't work at sea level, as others have pointed out, it would have to be underground to avoid thermal expansion issues... meaning higher pressure.