Coverage maps like these are no longer useful. I have "4 Bars" with extremely slow data rates constantly. My average speeds are about 1/10th what they were 7ish years ago (1.5 Mbps down vs 15 when networks were less loaded, "LTE" networks) as device density and usage has gone up.

We need data throughput maps, maybe even by time of day.

Having "coverage" doesn't mean you can actually do anything with it.