I worry that these COVID border closures have fatally weakened Schengen. They may be only temporary public health measures, but the symbolic effect of successfully restoring walls between Europeans could be devastating in the long term. You have national-level health ministers saying that they are not especially concerned about the difficulties of people who live in a community that extends across both sides of the border, or who drive back and forth for (sometimes essential) work every day.

When e.g. Macron has expressed opposition to the survival of Schengen in its current form, then it makes it easy for such leaders to resort to supposedly "short-term" border closures after COVID, having seen that they could easily get away with it during the epidemic.