I could go into exhaustive details, but the EU made absolutely no case to the British people why they should be part of the EU, and that case is still unmade. Brexit was an EU political issue happening inside the EU yet it and the British people were treated with ignorance and condescension, like it was a wholly British minor political issue and the very thought of leaving was laughable (openly laughable because Nigel Farage got laughed at in the EU parliament when he put it to them that he was going to make Britain leave, which he succeeded in doing). That case for the benefits of joining has still never been made, rather assumed as self-evident. There has been no publicity at all towards the British people that they could rejoin and it would be beneficial, which is the step the EU would reasonably take yet refuses to do. Hence the British people similarly have no interest in begging to be part of this organisation, the mechanics and political organisation of which is very poorly understood.