I just downloaded a new toy to play with, it's called Natron. It's a free Compositor and looks pretty cool. It comes with G'mic 2.2.2, so you can basically apply any G'mic filter to your video frames. It has lots of nice tools, all I have to do is figure out how it works.....

It must be the 'Intuitive user interface' that makes it hard to learn

I just watched a howto video here and it seems pretty good to use.
https://www.youtube.com/watch?v=5-ou9mEAoKg
This is what people want for video and animation.

'Intuitive user interface' is not what I would use to describe this program. It certainly works though. I've been playing with it and it has some real nice tools. But it doesn't play well directly with video files. It has trouble decoding the codecs and prefers to work and export image sequences. This adds another layer of work involved.

To be truthful, I haven't seen any capabilities that surpass what Aviutl can do so far. I'll play around a bit more to see what I can find. I figured out how to export after numerous tries...

Example using G'mic's Brushify Filter.