You heard #Adobe. Deep down you knew this was coming. Now all your art are belong to them. Time to move on to better things…
Kreative Suite
* Krita is your new design/painting app
* Kdenlive will give you video-editing powers
* glaxnimate adds 2D vector animations to you videos
* digiKam organises your collection images
https://kde.org/for/creators/
Also:
* Inkscape - create sophisticated vector-graphic designs
* Scribus - layout like a pro
* GIMP - need we say more
* Blender - ditto
I am super impressed by Blender, but there’s not really a substitute for After Effects yet, open source or otherwise.
Have you tried Natron? This software still needs some serious love, but maybe you can appreciate its potential as tool for people used to AE.