It solves a pretty hard problem that is a self-hosted video platform; a lot of places use YouTube to host videos, even if they aren’t doing so to make money through adsense, this is for their own site material, posting to groupchats, and similar purposes.
Issue is that otherwise you rely on platform owners like Google, who can decide to unperson you, your business, or an employee. It effectively happened to me, YT terminated my channel for unsubstantiated reasons, and hosting my own peertube is likely in the future to replace where I host my decades of video content.
Further, ideologically, we should be collectively moving away from “platforms” for what should be obvious reasons to those of us on the fediverse.
ISPs really tried to make plans specially that were covered in whole by these credits, because it meant they could get customers who otherwise they wouldn’t have at all, and of course for the ISPs that gave a shit, it was also just a good thing to do.