You ask how scientists take it on themselves to tell creationists they are wrong, and ask “Wrong based on what?”
You answered your own question by the quotes you included. Wrong based upon evidence in the natural world.
The evidence of the natural world shows that predictions based upon a model of an ancient earth and development and differentiation of life forms allows one to explain and predict natural phenomena. Predictions based upon the model of a young earth and the near simultaneous creation of and contemporaneousness of all species lead nowhere.
Which still doesn't mean its wrong.
You answered your own question by the quotes you included. Wrong based upon evidence in the natural world.
More like wrong based on the interpretation of the evidence using a naturalistic worldview.
The evidence that evos use to support evolution is the same evidence that creationists use. It's not the physical evidence that's in question (outside of frauds) but the interpretation of that evidence.
What evos see as evidence of common descent from original one celled creatures, creationists see as evidence of common design and variation within kinds of created life.