Case law, also known as common law, is a British legal tradition. Most of the EU does not follow the common law tradition. There may be supreme courts, but the notion of binding precedent, or stare decisis as in the US legal system does not exist. Appeal and Supreme court decisions may be referenced in future cases, but don't establish precedent.

<https://en.wikipedia.org/wiki/Precedent>

The equivalent doctrine under a civil legal system (most of mainland Europe) is jurisprudence constante, in which "if a court has adjudicated a consistent line of cases that arrive at the same holdings using sound reasoning, then the previous decisions are highly persuasive but not controlling on issues of law" (from above Wikipedia link). See:

<https://en.wikipedia.org/wiki/Jurisprudence_constante>

Interestingly, neither the principle of Judicial Review (in which laws may be voided by US courts) or stare decisis are grounded in either the US Constitution or specific legislation. The first emerged from Marbury v. Madison (1803), heard by the US Supreme Court (<https://en.wikipedia.org/wiki/Marbury_v._Madison>), and the second is simply grounded in legal tradition, though dating to the British legal system. Both could be voided, possibly through legislation, definitely by Constitutional amendment. Or through further legal decisions by the courts themselves.

Yeah I'm really glad we don't have common law where I live. It makes the law way too complicated by having all these precedents play a role. If the law is not specific enough we just fix it.

Also it breaks the trias politica in my opinion. Case in point: the way the Supreme Court plays politics in the US. It shouldn't really matter what judge you pick, their job is to apply the law. But it matters one hell of a lot in the US and they've basically become legislators.