The referendum was non binding. There were two general election, where people could have voted for parties opposing Brexit.

In 2017 they voted Theresa May to do Brexit. When she was failling to achieve the absurd idea of Brexit, that was propagandarized in 2016, People voted Boris Johnson in 2019 to "get Brexit done". Also Johnson won "in a landslide" gaining an 80 seat majority in a 650 seats parliament. That was a 62% majority, almost the two thirds often needed in democracies for things such as constitutional ammends.

People had three elections were Brexit was the main issue and they could have voiced a change of mind, or which conditions were necessary to still be on the side of Brexit. They had access to plenty of information, they had seen that the idea of Brexit they had in 2016 was in fact impossible, and how a real Brexit will look like. And still they voted Brexit again and again.

I am sorry for everyone that got fucked by Brexit, but the British as a sovereign people have made it abundantly clear, that the majority wanted Brexit, or was fine with Brexit. The first step to moving on from this, is to take the full responsibility, that they have. There is a very clear indication that rejoining the EU would be the best for the UK. But this only becomes viable, if the British people work through and accept their past.