I get the slight demographic change that
@TwoSheds mentions, with more older leave folk died (accelerated by Covid a bit too) and more remain youngsters now in voting age, but there are equally more than you think that feel the EU is punishing us and have switched to leave. Some others will buy into the increased nationalism we're seeing, with union flags everywhere and plenty will blame the EU for immigrants coming over the Channel etc...
It's by no means a stupid point, but I just don't share the confidence that remain would comfortably win now. For my family sample, they're from from East Yorkshire, with David Davis my mum's MP, so that is Brexit central! Remain is a massive majority on here and similarly on social media, but in the regions that just isn't the case.