After Effects animation file looks terrible when compressed for Vimeo.

[Craig Seeman]

Let’s try a few more straws to grasp at.
Try exporting from AE using ProRes4444 instead of Animation codec.

Try using YouTube’s “Content Creator” recommendations.
You mention Main Profile. Use High Profile. YouTube mentions 50,000kbps for 1920×1080. I think Vimeo mentions 20,000kbps (10 to 20 actually).

It seems like overkill but see how Vimeo handles it.

[Marius Crowne]

It looks the same. Crap.

I’m losing hope.

It’s phenomenally depressing to spend so much time on a project and then not be able to show it to anyone.

//M

[Craig Seeman]

Try on YouTube using their 50,000kbps High Profile CABAC settings and see how it looks there.