Why are the EU against the U.K. leaving them then?
What does the U.K. do for the EU that they want to keep us?
Is it that they think it will destabilise the EU?
Or is it basically financial loss to them?
Assuming you are honestly looking for an honest answer, Heat, I shall try and suggest other valid reasons.
The first is, indeed, the increased wealth by all members by having free trade access to 500 million customers, and all done with the highest regard and standards of quality and safety. (You can kiss both of these away when the UK becomes desperate to trade with any other country who'll now have us over a barrel.)
The best shared values, often influenced or instigated by the UK - because we
are bludy awesome, you know. We are a country that the world looks up to for decency, human rights, free press, fair mindedness, equal rights - common bludy sense.
The shared desire to influence other surrounding countries to show them the better way forward, away from communism, dictatorships and despots. (How ironic). Yes, part of this will be financial incentives, and the UK - as one of the wealthiest members - will and should be paying more than many other much poorer countries. It's a long gameplan - this is about getting as many countries as possible to work closely together, sharing the best values, economic growth and security. Isolationism and insularity has been shown historically to not work. Freedom ov movement - where would you like to live, work and retire Heat? (How about that wonderful EU country called the Republic of Ireland, because you may just have sealed your own 'fate'...)
You know what? The economic benefits of membership are almost the least of it to me. It's all about
values, quite simply the sort of world I want us all to be heading towards. Cooperation and mutual benefits.
And that's as far away from Trump's values as possible.