The technical standard is very high in the Bundesliga. The locals are technically very good, so the baseline is high. The problem is Germans have collectively forgotten how to defend. The national team has plenty of "footballers" - the problem is it hasn't a single defender worth the name. The days of Schnellinger, Beckenbauer, Breitner, Stielike, Förster, Kohler, Buchwald, Sammer, and Lahm are long gone. When Rüdiger is held up as your best defender, you know you're in trouble.
Thankfully, we haven't signed a German defender.