The UK doesn’t need the EU as much as the EU needs the UK. The UK is part of commonwealth nations. These 53 nations include India, Australia, New Zealand, Canada, South Africa, Pakistan. The Commonwealth predates the EU.
The UK’s economy was more advanced than any other EU nation. Leaving the EU doesn’t effect any trade with thier commonwealth partners.
In other words, it’s as true as ever:
“Fog in Channel, Continent cut off”