I was going to be kind with him and mention the Qatar blockade. But from what I remembered is that there is still exports via the see ( liquid natural gas). I think most imports are through their airline (Qatar airways), but obviously, the load factor would be low in comparison.
400 aircraft is not even the same as half a cargo ship probably. I can't even comprehend how big they are. We actually could probably handle 400 extra landings a day, but to have the same amount of cargo coming into the uk, we would need a hell of a lot more aircraft to be equivalent to what we currently get via cargo ships. I don't believe in climate change, but all that shit that comes out of jet engines falling down on us, even though they're by far cleaner than 20 years ago, that will fuck up our health.
The jets would have to be massive too. There are s limited amount of the an225s and an124s and Boeing have reduced the production of the 747-8f to x per year.
Imagine how big a jumbo is.... then look at them fat off cargo ships that carry hundreds of times the amount what planes can.
Aircraft are good for life limited/shelf life items though due to their speed and very small items, but obviously you won't get the same volume as a container, cargo ship.