The future of the EU isn't safe beyond all doubt, so there's a risk this'll turn into a self-fulfilling prophesy of EU doom.There is certainly more potential downside than a lot of people seem to realise.
The EU27 member states are not going to be affected in some uniform way by Brexit, particularly if we get the no-deal version without any sort of overall orderly transition. Those states that are particularly exposed to Brexit overall -- such as Ireland and the Netherlands -- stand to take a large economic hit, perhaps even worse than the UK itself in the Irish case. Other states may do fine in many respects, but specific industries or other collaborative efforts may be seriously affected.
This is why I find the Irish government's strategy puzzling: they continue to insist on a measure that has been a proven deal-breaker for an orderly withdrawal, which means unless they genuinely believe that the UK will fold and call the whole thing off, their strategy is almost certain to cause the maximum damage of any plausible outcome to their own country.
It's also worth saying, because it is relevant but rarely reported, that the economic models for different scenarios and how much effect they would have on various European countries' economies relative to a baseline no Brexit case do tend to assume that in the baseline the EU economy continues as-is or grows significantly. I have yet to see any serious economic model that compares outcomes for different types of Brexit against a no-Brexit scenario where the underlying problems with EU economics do then cause another serious problem or there is some sort of black swan event that affects the EU or Eurozone.