Unausweichlich translates to "inevitable" or "unavoidable". It's a strong, formal word that adds a sense of gravity and destiny to the lyrics.
In the song, it's used to describe a fight: "Ein Duell war unausweichlich" (A duel was unavoidable). This word perfectly captures the feeling of being trapped in a situation with no escape, making it a memorable and impactful choice.
Have you ever faced something you thought would be a huge deal, only to find yourself asking, "Ist das alles?" [Is that all?] That's exactly what Die Ärzte are getting at in this track. Our narrator goes through several experiences that feel monumental at the time, but each one leaves him feeling a bit… underwhelmed.
First, he confronts a bully he "alles andere als beliebt" [was anything but popular] with. He's terrified, expects the worst, and gets beaten up. But afterward, he just looks at the bully and asks, "Ist das alles?" Then, he gets a girlfriend, and things get a little spicy, but once again, the big moment passes, and he's left wondering, "Ist das alles?" Even when he thinks he's going to die from heartbreak, or when his father disowns him, or his boss fires him for being lazy, he realizes he's "einfach noch nicht mies genug" [just not miserable enough] to actually die. It's a funny, blunt take on how life's big dramas often don't feel as dramatic as we expect them to.