TLDR: It’s compatible with other copy-left licenses like GPLv3. However, it’s available in multiple languages, which technically makes it more applicable.
I started using it for my own project. If you want a practical example: https://github.com/TimoKats/emmer


A lot of the discussion seems to be US centric though, such as this quote:
Since this links to a US court decision, I believe the first part also refers to the US. As little as I know about EU law, what I do know is that it is often intentionally vague to ensure the spirit of the law cannot be violated. That seems to be the same for the EUPL where vagueness is preferred over concrete definitions which may hold up even worse in (EU) court due to the limitations on copyright law.