The "4K" label is cheap to print. Genuine 4K needs 15–25 Mbps per stream, HEVC encoding, and a server that can sustain it at peak. Here's who actually does.
Our bitrate verification protocol records 60 seconds of playback on each flagship 4K channel at peak (Saturday 8pm in each region), measures the mean and 5th-percentile bitrate delivered, and rejects anything whose 5th-percentile drops below 10 Mbps. That's the cliff where macro-blocking becomes visible.