You dont have to hit abs every day. You could go every other day and still get results.
That being said, a cardio workout doesn't replace an ab workout.. If youre scheduled to hit abs that day, then you have to hit abs.
hope that helps.
False
I never do abs and its one of my best areas
Nobody "has" to do anything
Progressively overloading on squats, deads, chin ups, push ups, overhead presses, dips, etc will all work your core and build muscle
The only person that "has" to do direct ab work is the soft person spending all day on machines