The only real problem right now is efficiency of spending. Nearly all public sectors (defense, housing, transportation, education, healthcare) bemoan significant lack of financing and workers. Yet, Germany spends enormous amounts of money and employs record levels of workers there. It's like all the money and workers just vanish. This leads to the situation that it's currently difficult to hire in Germany.
This process leads to the attraction of skilled workers especially from eastern Europe. I don't know where this ends, but I doubt the spending and employment will get significantly more efficient. Instead, Germany might very well attract additional millions of well-educated Poles, Ukrainians, Romanians, etc.
I wouldn't be surprised if by 2030 we see a Germany with a population of 90M people absolutely dominating the European market.