The entire system is designed for sending containers one by one in pods, so its throughput is not at all impressive compared to the trains with several tens of railcars.
Not to mention the technical difficulties of reliably maintaining vacuum in hundreds of kilometers of the tunnel. And don’t forget that a single broken seal anywhere on the whole track would bring the whole system to a halt, and would require significant safety intervals between the poss.
As for the speed - the hyperloop’s main advantage - there is relatively little cargo in the world for which shipping time makes a critical difference between 100 km/h train and 2000 km/h hypothetical hyperloop. Reliability, throughout and an established network are much more important, hence why the bulk of world’s shipping is done slowly and reliably by sea.