The EU is sovereign, it is, and always has been a project for member states to tackle issues at scale that would not make sense to duplicate on a national scale, and to reap the benefits together. Don't buy into the nonsense that being stronger together is somehow detrimental to sovereignty of member states. It in fact makes them less vulnerable to bad actors on an international such as the U.S., Russia, and China.
As I mentioned in another comment, if the EU is sovereign then member states no longer are, and if member states are sovereign then the EU isn't and still defers to member states.
That's why I think the way the term "sovereign" is thrown around is misleading and in fact part of push to transfer more control, and in fine sovereignty, to the EU from member states. People can decide if that's good or bad but the process is misleading.
HN is about curiosity and it seems that commenters do not use any as soon as the EU is mentioned but rather accept the official narrative without questions. The trend is to reduce member states' sovereignty, not to increase it, while the EU is taking over.