Animation component with SpriteRenderer won't preview/play anymore

This is a very weird issue because I've animated sprites many times in the past and suddenly it has stopped working.

I used the old 'Animation' component (not the Animator) to animate some sprites for a visual effect. When I tried to preview the animation nothing came up when pressing the play button or scrubbing.
Both the previewing and the playmode don't play the effect. However animating anything else but the Sprite Renderer component works.

I created a new project to make sure this behaviour is consistant across projects and it was also the case in a new project.

I did put the animation in 'Legacy', and I'm on Unity 2018.2.13f.

What makes the animation not preview?

Here's how previewing doesn't do anything:


Here's what the fx should do:

 

Still dont work in 2021 unity! Is using Animation component to animate Sprites is now impossible?