The author seems to ignore the fact that passing lambdas like this merely changes where the IF or SWITCH statement is made. I can agree that passing functions instead of booleans is better and more general. But pretending that IF/SWITCH are thus avoided, is delusional.

For instance, at some point there will be a decision made whether the string matching must be case sensitive or not. If the program can do both at runtime, the IF will be, perhaps, in the main (or equiv.).