Maybe it is my bubble speaking, but the only subtitle synchronization I ever needed were either a constant or a continuously increasing/decreasing offset, both easily solved without pretrained deep neural networks.
That's a good bubble to be in. I very often happen upon subtitles that need an offset, a constant multiplier because they run out of sync, and sometimes have a gap somewhere. It's very annoying, and I'm glad there's software to fix them without me having to faff about for ten minutes.