Delivery.
H.G.V. drivers deliver stuff. As Clark has suggested, if there is a tightness in availability of drivers, then drivers catch covid or are self isolating because of covid, or new drivers cannot be buddied up with experienced drivers because of covid, then there will be an operational shortage of drivers. Or new drivers can not take an H.G.V. drivers test because of covid. Or the Swansea lot do not issue new licenses because of covid there will be big problems.
I also think it is the delivery of Natural Gas, world wide that is a problem caused by the pandemic.
Things should shake down, in a year or two.