You summarize it well, but I'd like to add that most of the characters feel amazingly real. The language is a big part of that of course, but much of the rest is that the cast largely played people they knew personally. The extreme is Felicia Pearson, a murderess who is played by a convicted (supposedly second-degree) murderess of the same name.

I'm amazed at how well this series has aged. It looks copyable, but somehow nobody ever did - maybe showrunners would rather avoid the comparison? Even Breaking Bad, which started out somewhat similar, went away from the realistic and toward the cinematic after the first few episodes, and I imagine the reduced comparisons to The Wire were an intended part of the effect.

(Although now that I think about it, there's a German series ("Kriminaldauerdienst") that obviously copies The Wire. Makes sense though, because The Wire is practically untranslatable, and its German dubbing is atrocious, so you can kind of avoid that juggernaut if you hide inside the German language market. Maybe other non-English language markets have similar series.)

It definitely needs subtitles if English isn't your first language.