It wont really lose anything. UK can now start new "tax haven" initiatives (discouraged under EU) and companies will flock there better than before...
London didn't get its "preeminent spot in the world of finance" by entering the EU/EEC etc or because of it. It earned that spot by itself 100+ years before...
Not to mention EU is barely doing well itself...
It has been a global hub for centuries.
This problem gets worse when the past becomes an argument for not taking the necessary steps to mitigate any potential change.
The modern successful UK is almost certainly a consequence of closer collaboration with the EU.
Almost none of the reasons the UK was successful before are true anymore.
Is it? Or just neoliberalism via Thacher making it more alluring to modern capitalism (succesful for society is another thing) and the same cheap credit flood in the 90s+ that happened across the West?
Maybe the one asking had in mind some derelict tax haven islands in the caribbean or so? Not all tax havens are like that...
Reasoning doesn’t really come into it with brexit.
According to the EU. People who actually work in finance see it a bit differently.
Greater London residents voted overall ~60% to Remain, but you'd expect that traders live in the Eastern boroughs, and outside London, in Essex (both up to ~70% Leave).
Along with lots of business owners I know. All of them knew exactly what they are signing up for. The OP's message is precisely the problem with the argument from Remain. They didn't answer any question or worries they had with Brexiteers. ( Or they did but it wasn't really what they were looking for ) And the discourse then fell apart.