Is Great Britain's insularity an advantage or a disadvantage?

I will share ideas on both sides of the question so you can make an informed decision.
Great Britain’s insularity has been both an advantage and a disadvantage. One way their insularity has been helpful is that it has been hard to attack Great Britain. There have been attempts to invade Great Britain and several haven’t succeeded. The Spanish failed to conquer Great Britain with its armada. Napoleon talked about jumping across the English Channel but never did. Germany, under Hitler, had rolled through much of Europe, but the island location of Great Britain was too much for Hitler to overcome in World War II.
Because of its island location, Great Britain has remained very independent and hasn’t always felt the need to conform to European norms.  The recent rejection of the Euro is a good example of this idea.
Being an island nation also has been a disadvantage. It has helped to contribute to an image of a people who are resistant to new ideas, to other cultures, and to other ways of doing things. The image of the British being very reserved may be tied to their status as an island nation.
Being an island nation has been an advantage and a disadvantage for Great Britain.
https://www.telegraph.co.uk/culture/tvandradio/9505711/The-British-how-insularity-and-the-weather-shaped-our-national-identity.html