//it simply isn't true that Brexit was the culmination of some long process...//
I wouldn't say "simply" because nothing to do with the EU is simple, but I can tell you that the underswell of anti-Eu opinion in the UK goes back a long, long way. As I’ve said many times before on here, I decided in 1992 that, given the chance, I would vote to leave. I bided my time for almost a quarter of a century and nothing anybody said or did in between changed my mind. In fact my resolve was strengthened considerably when the Lisbon Treaty was signed by that nice Mr Miliband and (later in the day, because he was busy) Mr Brown. There’s plenty of articles available to explain this evolution but it is well known that the UK’s EU membership was a bone of contention among much of the electorate for many years and with each new “Treaty” – when further integration occurred – that debate was aired again. Brexit may not have happened if the country had been given a referendum on the Lisbon Treaty (as it should have been) but voters were not granted that privilege so the sore continued to fester. This is quite a succinct article which explains the evolution of the UK’s disillusionment with its EU membership:
https://brexitcentral.com/mark-francois-mp-appalling-handling-lisbon-treaty-sowed-seeds-brexit/
I did not expect any immediate advantages to follow from our leaving. I fully expected the EU to make it as difficult and inconvenient as possible and for them to continue to do so if and when we did leave. In that respect I was entirely unsurprised and continue to be so whenever problems which are “caused by Brexit” arise. What I did not expect was the obstruction and obfuscation that flowed from UK politicians and others, especially from the Tory side of the House. This is especially so when it was a Tory Prime Minister who told the nation, in writing prior to the vote, that his government would implement the decision of the referendum. That said I often urge people on here never to believe anything politicians (of any persuasion) tell them, so I should not have been surprised.