Nothing would change......apart from the inexorable march towards a centrally controlled unification of European states run by a democratically deficient oligarchy at its centre.
It would appear from your post viz Anglo American and worked in Europe that you have no particular loyalty to either side. That, of course, is your right but for those of us that see the EU experiment, albeit noble in its foundation but now an anachronism that faces financial decline and social unrest in the globalised world, there is only one way to restore that ability of the UK to determine, for better or worst, its own future and destiny.