This looks interesting. https://maurycyliebner.github.io/
I work as a graphics designer (mostly 3D animations). Back in 2016, I was working on a short 2D vector animation. I tried creating it with Synfig, but for some reason, I found it unusable. I am not trying to discredit Synfig, I am sure there are people who use it successfully. It simply did not feel right for me at the time.
I ended up using After Effects, which was a lackluster experience. During that time, out of frustration, I opened the Qt Creator and started a new project called AniVect. Back then I did not have any plans for it, I just wanted to write some code. I had no prior experience with graphics related programming, so I had no idea what I was getting myself into.
Introducing enve, free/libre 2D animation tool | Libre Graphics World