Figure 5.3 shows interaction model instead of main effect model

[MMJansen]

Version of the book 2020-02-01

Regarding fig 5.3 (Predicted probability of attrition based on monthly income and whether or not employees work overtime)

Model 3 is a main effect model. The model lines in figure 5.3 are made using geom_smooth(). This results in lines in which the interaction effect is also taken into account. A better way to illustrate the model with only main effects, could be just to plot the predictions from the model. I did this with modelr::add_predictions() :
churn_train3 <- modelr::add_predictions(churn_train, model = model3, type = "response") %>% mutate(prob = ifelse(Attrition == "Yes", 1, 0))