At the same time, there are things to keep in mind:
- this is asking member-states to delegate some of their sovereignty, which is never all easy and always involves quite a bit of horse-trading
- the member-states are perfectly happy to fuck things up on their own and things like growth figures for the eurozone actually mask very different realities depending on the country and its government
- stagnation is a very western point of view, things are still changing quite a lot on the eastern side
- the reference point should be the same situation without the EU. I am not sure, for example, that things would be improved with a trade war between Germany and France, the baltics fending off for themselves, or each country having its own import requirements and sets of tariffs.