Nearly had me agreeing
Until I thought, hang on. I pay for a 180mbps Internet connection. If I choose to fill it with Netflix then I choose to fill it with Netflix. If I choose to fill it with Spotify then I choose to fill it with Spotify (or Pi OS downloads, or any other downloads). If I breach your cap then my bad (if I agreed to it) but if not then why should you throttle data which I have already paid for? Don't have the capacity then don't sell it.
I'm sure there are arguments against Netflix doing bad things, but if the data throughput is less that I have paid for then it's less than I have paid for.