A nice benefit is curbing the scope. By reducing the block to a seperate method you are making it clear to future readers that this chunk of code only depends on the parameters given.
In pseudo code
$some_variable = "something";
$some_other_variable = "something else";
if(x < y) {
... lots of code ...
some_method($some_variable);
... more code ...
}
By extracting the conditional to a seperate method, it becomes clear that the logic within that branch does NOT depend on $some_other_variable.
If you have big methods with lots of branching and lots of variables, it becomes more difficult to maintain the method and you are more likely to inadvertently break something.
