"A phone using the latest connectivity tech would automatically switch between 3G, LTE, and 5G depending on what's available at the time."
The context (and what I know of 4G) seems to be that the phone will automatically switch to the fastest available signal... but then isn't that a problem with the phone OS? Surely it would be a cleverer approach for the phone to analyse data requirements and switch to the fastest available network only if the data speed required justifies this, and otherwise automatically switch back to the least power-consuming option.
Unless it requires a lot of power and/or time to switch between modes. Anyone know any more?