Where did you get that opinion? Germany is not doing great but OK in the group of Western countries, and its car industry is both very imporant and in trouble, so it's not an unreasonable opinion that things would be better without that trouble.

Imho, the german mentality just doesn't fit today's economy. Too risk averse, too conservative. Creativity is not really embraced.

The state of the german IT sector also shows that.

Most startups have nearly no moat at all and purely live off marketing with some sprinkles of corporate identity.

What is the cause?

Uh oh