Straight staircase for single-family house: Are the dimensions okay?

3 m x 4.32 m I deduce from the dimensions of the steps.

Exactly, that would be about right. I believe 2.97m x 4.32 gross.

4.48 m doesn't fit? Then it would be within the standard.

4.48 m doesn't fit? Then it would be within the norm.

Good question... to make it comfortable, we would have to add one more step and extend the staircase to 4.8 m.

INPUT
Height of the staircase	H	=2.97		m
Depth of the staircase	T	=4.8		m
Number of steps	n	=17

Step measure	s	=0.63		m
Safety measure	S	=0.46		m
Comfort measure	B	=0.11		m

Then instead of about 2.4 m, we would only have 1.9 m between the staircase and the terrace door... That would then be the passage between the dining area and the living area...

Now we have found the following terms on the internet:

... and if you keep googling, you will find other benchmark values. However, benchmark values are just benchmarks and nothing definitive! I only know the 19/26 benchmark. And that should be enough not to confuse the builder.

Is it still comfortable?

already hit the nail on the head: it is different for everyone and also subjective to assess. Lots of math that doesn’t help.

so that it is cozy,

Cozy can be uncomfortable for stairs. You can observe that with steps that have less height or too wide a tread. Who is planning that you have no confidence? A good benchmark for 280 stairs is 15 steps. 14 (in Viebrockhaus townhouses) are already exhausting.

4 meters deep at 3 meters high would therefore be uncomfortable for everyone both objectively and subjectively?

4 meters depth at 3 meters height would therefore be objectively and subjectively uncomfortable for everyone?

Yes. and also no longer safe according to DIN.