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I've seen people use Blender for 2d animation, it's become kind of a "multi tool", that should let you integrate it with any of the other features.
For raw 2d animation, Krita has some support, there is also Synfig and OpenToonz. For simple stuff, Gimp works in a pinch.
Blender is nice but last time I checked it was not well optimised for 2d animation, motion graphics. But maybe it's time to give it another go - I think it's one of the best open source projects ever. The other one you mentioned lack in the motion design department. Gimp still gives me nightmares.
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).
Sound really good, I actually used blender for video editing back in the day - but got annoyed by it's old interface. Than played a bit with grease pencil and basic modelling, animation - maybe it's time to dive full in. Will check out the video. Thanks!
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.