It's the whole process, you could always do with more drivers but you need to use the ones you do have more effectively and not leave them sitting around for hours on end. Some ports have more technology to assist in the processing of containers, London Gateway for example is pretty new. The whole world has a problem with the supply chain and the recovery from Covid. The shipping lines are profiteering and that is pushing costs through the roof.
The paperwork has not changed when you are importing from Asia and India etc. There is always loads of it but the UK does have one of the most efficient customs systems where everything is electronic bar a few documents that still need to be presented. So no, paperwork, is not the issue. It's volumes and speed.
Felixstowe, I believe was suffering from 1000s of Gov containers containing PPE that were left quayside.
The USA is suffering huge delays at places like San Diego and LA as well.