There has always been interest in animation editing in Inkscape but
there has never been a developer who has had enough interest, skill, and
time to do it.
I fall under the interested category. I have wanted to bring animation into Inkscape for many years now. I even wrote an extension
https://github.com/nathanjent/inkscape-animation-extensionThe extension allows me to create animations using layers in Inkscape. This is far from ideal as every change I make to the SVG document using the extension framework has to be reloaded into Inkscape when the extension completes. When doing 50+ frames(layers) it really struggles.
Recently, I have given up development of the extension to focus on learning to develop Inkscape directly and hopefully some day help implement the animation features myself.
However, like Tav said, I lack both the skills and the time.
It would be sad if support for SMIL in SVG is dropped before I get the chance to animate in Inkscape.
Any advice to take me from "I took a college course on C++ once" to "Inkscape Developer" would be appreciated.