If this penalty sticks, Apple could be looking for a new suitor. Something has to be the default search provider in Safari and other Apple products.
Does something really have to replace it? Why not a menu of options? Make the user choose something. If they choose Google, great! If they choose DDG, fantastic! Whatever it is, make it a choice.
The google annual cost to have Google as default search on iPhone is north of 20b, hence the number in the article headline. They also pay lots to Mozilla and others.