Wattages mentioned don't say under what kind of load
A lot has been written in Pan Docs about reducing power consumption, which is good, but the wattages mentioned in the specifications page don't say whether this is under heavy load or light load:
https://gbdev.io/pandocs/Specifications.html
Or what game was tested. The wording of that reducing power consumption page would seem to imply heavy load, but this isn't explicit.
These are not measured; these are Nintendo's official ratings printed on the back of each respective console. As such, I expect the values to be "theoretical peak power draw" as opposed to anything reflecting real world game behaviour.
If you want real world power consumption charts, this page is a good start.
Thanks. That could be mentioned in a footnote (and no wattage at all is listed for the Super Game Boy still.)