Actually, that's a really good point. I'd love it if the companies that review carriers and report on bandwidth, cost, etc. would also include the percentage of people who experience throttling due to congestion. Look at it this way:
- They all claim that they won't throttle you UNLESS you're over a set limit AND the bandwidth is in high demand.
- Thus, if they do throttle, it means that they have under-estimated the necessary capacity for a specific market
- As such, the need to throttle would be considered a black-flag and one could assume that, should they not find enough people over said threshold, they'd have to throttle "normal" users (since they can't add bandwidth on demand).
The only exception would be some limited short time event (natural disaster, Super Bowl, etc.) or a coordinated effort where all users agree "let's really F with carrier X and all stream a 4K movie at 5 PM today."
If region A has more throttling on one carrier over another, it may help me decide who is the right carrier for me in I'm in that region.