The projects are dead simple. I think if Youtube wanted to, the would have implemented this long back. It's probably a legal landmine and financial tar pit. But thanks nevertheless.
You’d be shocked at how hard it is to fund, start, and ship even a basic project at a company the size of YT or anything else in the Google/Alphabetaverse. It’s probably also a legal landmine and all that, but organizational friction’s more than sufficient to explain simple useful features failing to ship.
Don't forget how Google incentivizes projects, one gets promoted for shipping the project, not for maintaining it. If indeed this were shipped at YouTube, I wouldn't be surprised if it gets slowly deprecated or outright shuttered in a few years. It's better to keep it open source for everyone.
