Baseus has launched a series of new slim, high-tech third-party chargers equipped with gallium nitride (GaN) technology. One of them is rated to charge 2 devices at up to 60 watts (W) at once. This may make it a good companion for laptops such as the MacBook Pro.
https://www.notebookcheck.net/Baseus-introduces-a-120W-GaN-Quick-Charger.506654.0.html
This pretty much confirms my suspicion that the rated wattage of a charger is that of its output, not input, so the one tested before to only output 70W is either fraudulent or defected.