The image doesn't quite work because youtube needs a MASSIVE solution that works, scales, doesn't fuck up their infrastructure and on and on and on.
Meanwhile on the user front, all your doing essentially is just skipping parts of a video, that will always be infinitely cheaper easier to do. Challenging for sure, but the solution can be small.
Even something as stupid as delaying your video start by 1 min, pre buffering then skipping ads. It's brute force and barbaric but the point is that Google can't do shit against that.
My ultimate vision is AI that preloads videos you want and detects ads / sponsor segments and just skips them / cuts them out on your device.