The whole point is to not charge users twice for both the volume AND the rate of flow.
It's not hot button because there is no FCC chair. If the dems seat a chair, regardless of who it is, that would allow grassroots campaigns to reactivate.
Under Trump, I believe broadband ISPs were implementing data caps, and they backed off on that after Biden was elected. And some telecoms offer zero rated content. It's far more common overseas for telecoms and content providers to partner in providing access, so you get places like the Philippines where Facebook basically is the internet.