Natron is essentially the FOSS version of Nuke. And Nuke may seem overkill, but using it for simple tasks at first is a great way to familiarize yourself with the tool before using it for more complex ones.

I used to use Nuke just to do some colour grading, or composite two animations together, back when I was in school for 3D animation. "Simple" stuff that Blender could've handled, but I liked how Nuke was designed specifically for composition and VFX. The focus helps, I find. Which made me happy that Natron is a thing (although I recall it having some stability issues with me).

I use it for basic 2D animation - overlays for videos (captions, title sequences, etc.) and animated diagrams - it works really well when you get used to it (mastering the curves editor is essential!). If you're going to composite what you do onto video outside of Blender (I use Resolve) you need to export as an image sequence in a format that supports transparency (e.g. png).

For more complex 2D work, Marco Bucci has an interesting three-part series here (the third part goes over animation specifically).

Blender is constantly evolving, so it's worth checking on it at least periodically (maybe every 1 or 2 years). Over the years there have been a lot of changes to the interface, and there is a general roadmap towards making it work in a non-destructive node-based way for all workflows. Which is an immense undertaking, but the development is happening somewhat in parallel, meaning that at any moment you may find any part turn from not being well optimized, to becoming a killer feature.