I know you are not dissecting your question too much, but asking a general one.
The examples you showed have several components.
- They are built obviously in 3D software. You can google a list of the most widely used, but we need to limit your search because there are many different modeling techniques. Some are used to make organic stuff, some others to create landscapes, clothing, etc. You name it.
So, first of all, look for software used for hard surface modeling.
Obviously it has realistic materials applied and a nice-looking rendering. That specific look (Pocoyo Style) is one called Ambient Occlusion. It is a fast way to render images without "too complex" calculations.
Some of the pieces are simple keyframes. "This piece goes here at second X". But some are a series of them consecutively. This needs to be controlled parametrically. Normally you use software for motion graphics.
Then, you need to look for "the usual suspects" used in the Netherlands? or France? But probably that is not necessary.
There are some other issues, for example, if the cross sections are prepared based on some other part of a process, let's say CAD software. But as they are only for presentation purposes, I think that is not a real element here.
There are many programs that could do this and, again I do not know which one they used. But for the "parametric" animation, I would look into Cinema 4D, 3D Max and Blender.
For the price (free but not cheap at all) and the accessibility, (you can use it right now) I would use Blender.
Look for "Blender Geometry nodes" and "Blender Animation Nodes" on youtube.
I must add that animation nodes is an add-on up to Blender 2.93.
Some animations can be done on the latest build of Blender 3.2 with the included Geometry nodes.