What good animation does
Good animation guides the eye: it shows what to read next and makes the page feel carefully made. Bad animation makes people wait. In these designs the content is there from the start, and the movement is added on top, so nobody has to sit through an intro to read your work.
Animation that does not get in the way
The text of your page is plain server-rendered HTML, readable with no JavaScript. Effects load separately, and anyone who has asked their device to reduce motion sees the finished state.
If you are applying to a conservative employer, keep an animated page for your creative applications and switch to a quieter design in one click when you need it.