You’re wayyyyyy oversimplifying it. The problem is the amount of data use today. LTE networks from even a few years ago would not remotely be able to handle it. High-band 5G and mid-band LTE/5G is necessary to alleviate congestion from low-band LTE

No truth at all.

Not exactly true. 700MHz LTE actually had better range than 850MHz 3G, which is the lowest frequency that 3G used across any carrier. All of the carriers now have 850MHz 5G, and T-Mobile has 600MHz 5G which reaches even further.

The network tech used doesn’t determine the range of the signal, only the frequency does. The difference is that low-band signals are so overloaded now which causes their range to significantly decrease

4-5% is excessive. Battery health might be misleading? Especially if the device has been sitting idle for a long time. That’s the only thing I can think of.