Yup. Sadly, discussion of Brexit on HN is trash tier. Almost every claim about it you'll find here is completely wrong. Not in the sense of differing values or priorities, but in a "this is totally made up" kind of way. It's really concerning that so many people's understanding of the UK and Europe have suffered such a huge rupture with reality. The map is not the territory!
Leaving the EU had no effect on the British economy. Not positive, not negative. Even the trade balance with the EU merely continued along its long term trend, so apparently the single market wasn't delivering any value in the end. The closest thing you can find to an economic impact was the currency dump that happened the moment the result was called, but the economy did fine in the post-referendum years and so those traders who panicked just took a bath and the currency recovered later. Not that a currency devaluation is such a bad thing for the UK anyway, its exports could use the help.
Even some non-economic impacts failed to materialize, in both directions. The UK rejoined the Horizon research programme (supposedly a "cherry" that would be lost), but also the reduction in immigration that voters were promised didn't happen either, in fact immigration went into overdrive.
A lot of people who support the EU don't realize any of this, partly because the news doesn't report on things that don't happen so they never hear about it. But mostly it's because they conflate predictions with reality. For example, there's someone saying in this thread that "the narrative was pretty catastrophic" followed by "I don't know how things panned out". And when I pointed out this lack of impact less than two weeks ago here, I got a reply that cited another pile of predictions as a refutation:
https://news.ycombinator.com/item?id=43469356
It's a systemic problem that crops up in other areas too. During COVID modeling predictions were regularly repeated as if they'd already happened, and you see the same mental slippage in climate change discourse. The line between "we think this might happen", "this will happen" and "this has already happened" blurs to nothing.