Is emergency opening for blinds on the upper floor absolutely necessary?

The child at 3 years old will hardly be able to roll the shutters up

Pffeffersprayer's child is not even that old yet, I estimate about half a year. But a 6-year-old can certainly crank, and so can the mom with the cat under her arm.

That’s why I wrote that it is not meant entirely seriously. Nevertheless, the two statements confuse me when compared to each other. But yes, I do trust the fire brigade to remove the roller shutter in seconds. The guys I know are not very delicate. A child is a different matter, but if it is capable and not shocked at the moment, it will be able to kick against a roller shutter. But ultimately, of course, I don’t want to find an argument against the crank; it makes sense in any case. It can save lives.

If the blinds cannot be raised due to a power outage during a fire and the fire brigade is called out, they won’t even know which room on the upper floor they need to enter. If you’re unlucky, they will break all the other blinds first before realizing that you are in the last room. And it simply takes a few minutes until they, standing on the turntable ladder, break down the blinds without injuring themselves. Especially if there is a closed window behind them.

And if the fire is so severe that you can no longer wait for the fire brigade, then you just jump out of the window.
It’s alarming that the main contractor doesn’t have this on their radar; you definitely should not try to save money on this.

It also can't be just any window, you have to be able to ladder it and it has to be accessible. Behind a solid fence is sch

But I would be interested to know how that's supposed to work? The window is usually 4m above the ground.

As was written, it is about the rescue route, not the escape route. The fire department must be able to ladder there and the window must be suitable (dimensions, sill height).
At the neighbor's, they even advised based on the existing equipment whether the planned rescue route would work (it didn't).

What consequences (apart from a serious situation like a fire, etc.) can I face for not having a second escape route?

Can the insurance refuse to pay? Or can other sanctions be imposed on me?

Well, theoretically you do not get a building permit. But you probably already have one. In practice, the consequence is probably only a failed or too late rescue in the case of the very worst accidents.