I think if you view it from this angle it becomes clearer: The court has not arbitrarily declared GA illegal, it just follows what the GDPR mandates - and came

I think if you view it from this angle it becomes clearer: The court has not arbitrarily declared GA illegal, it just follows what the GDPR mandates - and came to the (quite obvious) conclusion that GA is not compatible with the GDPR. Consequently it is illegal everywhere where the GDPR applies. This doesn't mean that there are immediate consequences for those who use GA on their websites in any other country, but it is very likely that other EU countries' courts will decide the same way.