@JoeyKramer Executing an algorithm can lead to further insight to its working, in my (unreliable) experience. It is the difference between seeing something happen and doing it yourself. (I don't think the comments here are a good place for having this discussion.)

@JoeyKramer Doing it by hand might help in understanding how to draw for example $f(x/2)$ or $f(x+2)$.

Have you done this, and did it teach the students to read textbooks, expositionary parts or otherwise?

Negative numbers as debt were understandable to kids in seventh grade, but I'm not sure when it becomes understandable. One kid has 3 €, another has 1 € of debt, third one has 9 € of debt. Who has the least money?

@JoeTaxpayer Feel free to ask the other questions if they interest you.

I edited the question a bit to emphasize that the question is about what the teacher draws.

@DanFox 1. In the new curriculum (in Finland) intersubject or interdisciplinary teaching is emphasized. Leaving drawing to the art classes seems counter to this. 2. The middle school also prepares students to enter a vocational school and to be in general well-rounded adults. Measuring wood and cloth and drawing lines to cut or paint by is part of this, I think, and also a fine application of elementary geometry. 3. Do you argue that precise drawings at middle school are disruptive for the development of abstract geometrical reasoning? Is so, please write an answer; I'm interested.

@DanFox Computer programs are not very good at drawing accurately on wood or cloth, or at least that requires specialized equipment.

I'm not going to accept my own answer, but some of the arguments did not appear in answers of others and I do think they are worth recording.

Related, but with no satisfactory answers yet: matheducators.stackexchange.com/q/10540