Ripped cable connecting (damaged) display to phone - worth fix?

@hacknslash730 no you can’t replace the cable since that is “Very” soldered to the display assembly and consider it part of it. Replacing your display assembly should resolve all the issues. Since you are already working on it I do not think that suggesting you go to the Apple store etc. is a somewhat moot point. Anyhow, follow the directions given on here iPhone XS Max Screen Replacement for a successful repair

If your phone is in warranty or if you paid $ 5.99 for AppleCare + coverage, your iPhone is covered for up to two incidents of accidental damage with just $ 29 extra for the screen repair, so use absolutely Apple to fix this broken screen.

You can bring a damaged iPhone to an Apple store or authorized service provider for a screen replacement, which can often be done the same day, or you can ship your iPhone to Apple in a shipping box provided at your request. . Expect to be without your phone for a long and exhausting week, but if you live in an area without easy access to Apple stores or partner locations, this is a good option.

If your iPhone doesn't have a coverage plan, you can try taking it to a cheaper screen repair shop. Just make sure to back up the iPhone to iCloud first because you never know if the low rate transaction might end up accidentally damaging your phone. If this happens, it can also void any iPhone warranties you have.