There is a middle ground. Why people only think about two options: a federation of states like the US of EU, or every nation by itself? Why can't EU be a free trade zone and a way to align national laws in accordance with a common standard?

EU seems to have entered the wrong path when Euro currency was established. There is no way in hell that countries with stable (very slightly growing) economies, and countries with a lot of catching up to do (fairly high growth) can coexist in a single system of money supply that is pegged either to one or the other requirement, but not both. This is a purely economic issue that will kill EU in the long run unless some countries agree(or are forces to) take a hit for the team.

Second, the bloody arrogance of the (now previous)EU council. If they at least tried to demonstrate some wilingness to reform before the brexit referendum the result might have been different. Also, multiple examples of extreme hypocrisy.Few are:
- Pointing out "issues with the rule of law" in Poland for example, while being completely quiet about police brutality in France and violation of human rights in Spain where people got 20 years in jail because they organised a referendum!
- Threatening sanctions over Italy's budget not meeting EU requirements and at the same time chuckling answer "because it is France ;-)" when asked why same measures are not applied to France when their budget also doesn't meet the deficit requirements.
- Crying about lack of "solidarity" when Eastern EU countries didn't want to take Syrian migrants that were supposed to be forcefully relocated there (despite countries such as PL having and supporting over a million genuine war refugees from Ukraine) and at the same time Germany attempting to circumvent solidarity in EU and EnC energy policy by changing its law in an illegal way (it is an EU wide law that everyone agreed to).
- Crying about "issues with democracy" in Poland because their friends loose every election(despite the highest voter turnout in 20 years and much higher than previous diversity of parties voted into the parliament). One of the chief "issues" is politicians becoming responsible for electing some of the high court judges - while in other EU countries ALL court judges are either elected, or straight nominated by politicians and there are no "issues" with that.
- One day supporting green technologies and solutions, the next day trying to force in a law that requires trucking operators to "come to base" at least once per month (even when empty) that would very signifficantly increase waste of fuel and increase co2 emissions by the trucking industry - why do they want that? A hint is that west EU trucking companies are loosing 90% of its business to Eastern companies. Western politicians are willing to throw the climate issues under the bus if it means helping their own truckers.

Those are the problems that are killing the EU. However, there are many people, me included, that don't want EU to be destroyed. We want logical reforms, not propaganda, no arrogance, going back to EU's roots when being in it was an advantage for all of its members. There are still millions of people that still believe EU should be about free market, freedom of movement, standarisation of law, true democracy and benefit to all of its member states and nations. There is no reason why it can't fulfill that purpose.