it's more like a glass bottom, and for good reason because corporations in Germany (also in the Nordics) have a stabilizing social function. Firms exist to consolidate towards higher productivity. The idea is to avoid an army of one-man businesses without healthcare or insurance or any significant output.
In practice it becomes an invisible glass ceiling, you just work/pay your way through it when it's time, otherwise keep playing in the shallow end for as long as you want.
Win-win, surely, but patronizing nevertheless.