[kazga]

> I am yet to meet a non-native speaker who wouldn’t have a horrible accent and who wouldn’t make a lot of mistakes

Even the most fluent non-native German speakers I know still mix up genders and adjective endings every second sentence, at least in speaking.

[Quequau]

I am losing my hearing and I have found that this effects my understanding of German, which I learned late in life, far more than English, my native language. In fact I'm convinced that many native speakers of German simply do not enunciate articles or adjective endings and native listeners simply subconsciously understand what they expect to hear because that's what is correct. Likewise I'm sure that native speakers of English do similar things but because it's all subconscious I can't give exact examples.