Hello,
you have already answered the ever-popular question about equity capital ;) If I estimate your wife's income, she earned about 1k net before. That means you had tax classes 3 / 5. From the equity capital side, I can only say that it is too little. Even if the kitchen etc. are present. It usually turns out differently than you think. The interest rates are one factor, but not everything. When the market turns, prices will also come back down.
I also don't know why so much one-time payment is put into a retirement provision that is also with the employer..... But well
Your arguments are justified but do not all entirely apply. The capital that I called "security" is practically an additional bonus from my employer. I myself do not pay anything into this pot. But nevertheless, I have invested a lot in private provision which is supported by the company. Why? I simply have the best conditions here which I can't get anywhere else.
The tax return class is another story. We have been together for 10 years but have only been married for 9 months. Tax class 3 has therefore applied to me only since last year, whereas before I roughly paid €800 more tax per month. By the way, my wife's income was around €570 net, she only worked 60% in a poorly paid job.
Still, I "gladly" accept being reminded of having too little equity capital. With more discipline, there could have been much more, but needs in life change, not rarely with increasing age. As I said, we are not going to rush into such a life task as a house at any cost anyway. The possibilities must face reality, even if they would currently level our project. Then it's just save save save.