The vast majority of folk voted with integrity and for what they believed would give the best future for the UK.
Unfortunately, a lot of lies and misinformation was peddled by Boris Johnson, Nigel Farage et al.
Immigration - we did have powers to restrict immigration for 7 years from new members and also to remove immigrants if they were not financially able to support themselves after 3 months. The UK gov chose not to use these powers!
Economy - we give a tiny fraction of our annual spend to EU and have absolutely had our money's worth.
Rules - again, a small % of our rules are made via EU. These have been made with UK as an equal partner at the table. many are about workers' rights,fairness, and environmental protection.. if we want any trade with EU in future, we will need to adhere to many of the rules, but without any say.
I was watching EU parliament this morning debating last night's UK vote defeating May's deal.
The overwhelming response is concern for the impact on UK ( and EU) citizens in the event of no-deal/bad deal. They are also open to UK staying in EU. There isn't and never has been any impression of a desire on the part of EU to be obstructive or impose penalties on UK.
Finally - to say we must leave as the people voted to leave and to change our minds would be undemocratic is just not the case. If a group of friends chose a holiday destination based on a glossy brochure and then found out the brochure didn't reflect the reality and the hotel was half-built, dirty and responsible for many cases of food-poisoning, who in their right mind would say " We voted for that hotel, it would be wrong and undemocratic to change our minds.We're going to have to go anyway, no matter the risks"?