"EU" is too broad of a term to describe cultural/social/political norms such as public toilets. There are places in the EU with fairly decent toilets, and others with almost none. In some you have to pay in many public toilets, in others they are free. The best bet in most places are public buildings such as libraries. And very often cafes etc allow you use a toilet, esp if you have health reasons and ask them nicely, though ymmv. The biggest issue as others said is vandalism, so in (richer) countries where public toilets are cleaned more often the toilets are much better.