For movies/tv shows/games we probably spend few TB a month.
I had never heard about such thing until now, it's ridiculous to have cap and I'm so glad that I don't have to live in such a place.
lets say a month is 30 days, a day 24 hours, an hour 3600 seconds, then a month is 2.592 Ms.
so an "unlimited" plan at say 1Gbps is actually always upper limited at 2592 Tb (bit) per month or 324 TB (byte) per month
I think governments should ban the "unlimited" names and force the ISP's to simply state actual limits or variable limit calculations if dependent on congestion. Here in belgium we have instead some vague "reasonable usage" policy...
There's one fundamental difference: there's no risk of exceeding that implied "data cap" derived from the speed cap.
You can find a non-capped (at least in theory) plan everywhere if you pay enough of course.