Why do these crazy governments appear everywhere, constantly fighting and pitting people against each other? That they don't live in peace? All these borders, possessions, the army - these are the wild times of the past. After all, it is good to be in a single Union without borders, without customs, with the same money. Probably, European officials have tortured everyone with their mediocrity and uselessness - they are paid money but they do nothing but stupid shows about enemies all around. I know this very well from the structure of the USSR.
Now we have a union of several countries: Belarus, Russia, Kazakhstan, Kyrgyzstan, Tajikistan, and Uzbekistan = Eurasian Economic Community. We live in one country in past, now we are all independent countries, each has its own currency and its own power, but we have no borders, we share the same laws to a large extent. This is very convenient: I can safely go to Minsk and even live there without fear of ignorance of the law, I can safely sell products in any country as well as at home. There is some tiny shared power, but it is invisible, does not interfere with anyone, does not command anyone, only coordinates various interactions. Yes, and all under the protection of the Russian army. Imagine all the countries in such a Union.
The EU is quite different from the USSR, which was an empire, gained through conquest, much like the British Empire. The member states of the EU all agreed to join, of their own free will. They weren't forced join, as was the case with the British Empire, or Russian Empire, which went on the be the USSR.
Many countries sharing the the same rules and currency brings a range of benefits, regarding trade and freedom, but it also has downsides too. Getting the EU to change a certain rule is challenging, because it has to be agreed between all member states, which can result in unnecessary delays. A classic example is the COVID-19 vaccine, which was swiftly approved by the UK, but will take awhile for the EU to agree on it. The same rules/currency are only any good when all states have similar levels of wealth and rule of law. The UK is more wealthy and has better rule of law, than many Eastern European EU states, so faces a lot of immigration from there and follows the EU laws more strictly. Immigration is not always a bad thing, but it's one of the reasons why many voted to leave.
In my opinion, the EU expanded too quickly. They allowed poorer, Eastern European countries to join too quickly. The reason for this is because they wanted to lessen Russia's influence, over Eastern Europe, which has caused trouble in some places, such as Ukraine.
I largely agree that unions of states and trade agreements are good things, but for practical reasons, only strong unions should exist between countries with similar enough levels of prosperity, rule of law and culture. States with larger gaps in wealth and rule of law can have trade agreements, but they should be weaker.
I read about brexit here and I am more and more convinced that the EU was needed first of all so that the Europeans would not fight again. 
Guys from England, but who chose Johnson? You didn't participate in this?
Yes, the original intention for having the EU was to put an end to war. The problem is the war has faded from living memory and the EU has engaged in feature creep.
I did not vote for Brexit. I backed remain. One of the problems is the vote was won by a small margin. Taking into account for the fact not everyone voted,
most of the people in the UK didn't vote to leave. There should have been a clause in the referendum stating that, Brexit would only occur if the majority of those who were eligible, voted to leave. Unfortunately, given that there was no such clause, we must leave the EU and not just in name only, as some politicians want. It's the only way to stop the government from losing any more trust, than it already has.